Opossum Reproduction, Pouches, and Babies (Explained)

Opossums really are remarkable creatures. They are the only marsupial outside of Australia, have a voracious appetite for ticks and other pests, and demonstrate one of the most fascinating reproduction cycles in the animal kingdom.

Because they are marsupials, their babies are born incredibly early and must spend the first few weeks of their life tucked away in their mother’s pouch. The pouch serves almost like a womb and provides a safe, warm, nurturing environment for the babies to continue to develop until they can survive on their own.

Opossums are found throughout North America and are roughly cat-sized when fully grown. They have a pointed face, white, gray, and black fur, and a long hairless tail which they use to hang onto tree branches.

When Is The Opossum’s Breeding Season?

As opossums only live up for around 3 years in the wild, they want to have as many opportunities to breed as possible. This has developed into quite a long breeding season which begins around February and lasts until September – that’s around 9 months, which can mean an awful lot of opossums.

Depending on the climate, some opossums may begin their breeding season as early as December and continue through to October. During each breeding season, a female opossum can have up to 3 litters of babies.

How Can You Tell A Male From A Female Opossum?

A fun little fact about opossums is that the males and females have names that are as cute as they are! Male opossums are called jacks and females are called jills, like the old nursery rhyme ‘Jack and Jill’.

If you are observing an opossum from a distance, you can guess if it is male or female by its size. Males usually weigh up to 15 pounds and measure about 28 inches long, including the tail. Females are a lot smaller, weighing in at 8 pounds.

Males can also be identified by the patch of yellow fur on their chest which is produced by a gland under their skin. Females also have a pouch across the underside of their body which they use to nurture and protect their babies.

What Is an Opossum’s Pouch?

Opossums are marsupials, just like kangaroos and koalas. If you have ever seen a cartoon of a marsupial you may have noticed a pouch that extends across their belly. The technical name for this is the marsupium, hence the name marsupial, and serves as a safe place for the mother to keep her babies while they grow.

What the cartoons get wrong is that in opossums the pouch actually extends vertically across their belly – so between their back legs and upwards towards their chest – rather than across their lower body.

The pouch is surrounded by muscles that can contract when the mother senses danger to shut her babies safely inside. The pouch is warm and safe and houses the mother’s teats where the babies get their milk.

How Do Opossums Find A Mate?

Dating can be hard for humans, let alone the naturally solitary opossum! Opossums will happily spend most of their lives alone – the only time they seek out other opossums is during mating season.

To do this, male opossums will make a clicking sound that attracts any nearby females. Females will only approach the males if they are fertile, in season, and if the females are not already pregnant or carrying babies in their pouches.

Do Opossums Mate For Life?

Opossums do not mate for life. They are rather efficient when it comes to the business of mating and will get it over with as quickly as possible before going back to their solo way of life. Once mating is complete, the male opossum will go on its way leaving the female to give birth and then care for the babies on her own.

Come next mating season, the male opossum will seek out a mate again, but won’t trouble himself to go back and look for his old mate.

How Often Do Opossums Breed?

Opossums only live between 2 and 3 years old in the wild, becoming sexually mature just under one-year-old. During the 9 months of the breeding season, a female opossum will give birth to between 1 and 3 litters of babies. Over her lifetime an opossum could breed between 2 and 6 times depending on when she is born and the kind of climate she lives in.

Do Opossums Only Mate With Other Opossums?

This is a question that has fascinated the field of natural sciences for centuries. Of course, opossums breed with other opossums – but can they make a hybrid baby with another animal?

First, we need to remember that opossums are marsupials, not mammals, so it is unlikely that hybrid offspring will survive from the start.

Second, although there have long been stories of opossum-cat hybrids or even opossum-dog hybrids, modern DNA testing has yet to find any evidence of opossum/cat interbreeding. Sometimes an ugly cat is just an ugly cat. (And if you ask a real scientist, you’ll learn that opossums can’t interbreed with other species.)

How Do Opossums Mate?

The intricacies of opossum mating are quite similar to mating seen in cats. The male opossum will climb onto the female’s back and grab a mouthful of her neck in his teeth to keep her still. Mating only lasts a few seconds before the male opossum lets the female go and wanders back off into the woods on his own.

Do Opossums Make Any Sounds When Mating?

No, they are remarkably quiet animals. Opossums are prey for larger animals like dogs so try to stay as quiet as possible unless it’s an emergency. The only time you will hear an opossum making any noise is in the following scenarios:

  1. When a male is trying to attract a female during breeding season, he will make a loud clicking noise with his mouth.
  2. When a baby has lost its mother it will make a very quiet, very cute, sneezing noise to let mom know where he is.
  3. When mom has lost one of her babies she will make a soft ‘ch ch ch’ sound, a noise that is somewhere in between the breeding male’s clicking and the baby’s sneezing sounds.
  4. When an opossum feels threatened it may make a hissing noise very similar to the sound an angry cat makes. Opossums hiss a lot, but they are rarely aggressive to humans so don’t worry if you encounter a hissing opossum – just give it a bit of space.

Is It True That Opossums Have Two Penises?

Technically, opossums have a forked penis, not two separate penises. For many years it was believed that opossums reproduced by the male breeding with the female’s nose – you can see why, the male has a forked penis, and the female has two nostrils. Females had also been observed to sneeze into their pouch, which led people to believe that the mother sneezed her babies out.

Fortunately, we now know that’s not true. Males have a forked penis because females have a bifurcated (another word for forked) vaginal canal. So the opossum penis is just made to fit the opossum reproductive tract. Why this started is a bit of a ‘chicken and egg’ question – but certainly, an interesting thing to ponder.

Do Male Opossums Have Pouches Too?

No, only female opossums have a pouch. Males don’t need one because they leave shortly after impregnating the female and have no part in raising the babies.

Another reason for males not to have a pouch is that the pouch is also where the female’s teats are located. As males don’t lactate, they have no functional teats and therefore no pouch in which to house them.

How Can You Tell If An Opossum Is Pregnant?

If you see an opossum with a swollen belly, it’s not pregnant – it has already had its babies and is carrying them in her pouch. Opossum babies are the size of jellybeans when they are born, so even a full litter is unlikely to make the mother’s belly look particularly swollen.

A litter of newborn opossums in their mother’s pouch.

Once the babies are born and have made their way to their mother’s pouch they will latch onto her teats and begin to grow. In the first few weeks of their lives, they can triple in size which eventually leads to the mother’s swollen belly which is mistaken for pregnancy.

How Long Are Opossums Pregnant For?

When a litter of baby opossums is born the whole gang can fit onto a teaspoon. Unsurprisingly, this demonstrates how short the gestation period for an opossum really is. Once fertilization of an egg occurs, the mother gives birth just 11 to 13 days later.

By the standards of almost every other type of animal, marsupial babies are born when they are essentially still fetuses. They still have an incredible amount of growing and developing to do which they can get on within the safety of their mother’s pouch.

What Time Of Year Do Opossums Give Birth?

The opossum breeding season is quite long, and up to 3 litters may be born in each season, so it’s tricky to determine when most opossums are born. The rule of averages comes into play here, with experts estimating that most opossum babies are born between February and June.

How Do Opossums Give Birth?

After the short gestation period, opossums will give birth to tiny babies that look like little pink, hairless, eyeless jellybeans. They are so tiny that they won’t survive for more than an hour without the safety of the opossum’s unique parenting style. When the mother begins to give birth she will start to lick a track from her birth canal to her pouch to keep the fur moist.

The babies are born and begin their slow and difficult journey to the warmth of the pouch by grabbing onto the fur with little claws and using a swimming-like motion. In the pouch, the babies will attach firmly onto a teat and begin to drink milk.

What Is A Baby Opossum Called?

A baby opossum can either be called a joey, like a kangaroo baby, or a pup.

How Many Babies Do Opossums Have In A Litter?

The number of opossum babies in an individual litter decreases over time. When they are born there may be as many as 20 babies making their way along the difficult route to the pouch. But once they are attached to teats and growing this number falls to an average of 8 or 9 infant opossums. We’ll talk more about why this happens later in this article.

How Long Do Baby Opossums Stay In The Pouch?

Baby opossums stay in the pouch for much longer than they were in the womb. When the babies are born, they are not viable (meaning they can’t survive in the open) so must stay in the pouch for 2-3 months. A larger litter will need more time in the pouch as there is less milk to go around and they don’t grow as fast as smaller litters.

When Do Baby Opossums Open Their Eyes?

A baby opossum will open its eyes much later than other baby animals. Anywhere between 2 and 2.5 months is normal for an opossum baby to first open its eyes.

What Do Baby Opossums Feed On In The Pouch?

Once in their mother’s pouch, the only source of nutrition for the baby opossums is their mother’s milk which they drink directly from her teats. This milk drips slowly from the teat continuously and helps the babies to grow nice and strong.

Opossum milk is very different from cow milk (so don’t try to feed a lost baby cow milk!) and is full of all the specific antibodies, nutrients, and vitamins a baby opossum needs to thrive.

Is It True That Opossums Have 13 Nipples? (Why?)

Yes, this is true! Nipples is another word for the teats which babies latch onto to drink milk. It may seem like an odd number of teats, but there is a very good reason. A mother having 13 teats limits the maximum number of offspring that can survive.

The journey the newborn joeys must make from the birth canal to the pouch is long and difficult, so the mom gives birth to a huge number of babies to increase the chances of more making it to her pouch. If this was a particularly large litter, upon arrival at the pouch they may find that there are not enough teats to go around.

This is nature’s way of ensuring that the mother is able to produce enough food for herself and her babies and limits the number of opossum joeys who will make it past the first few hours of life. Too many babies, and too many teats, and the mother will not be able to eat enough food to ensure their survival.

How Does An Opossum Mom Care For Her Babies?

An opossum mom has a full-time job when it comes to raising her babies. She must find enough food for herself to make sure she can produce enough milk for all of her babies. Then, as they get older, she needs to keep up her strength well enough to carry around a brood of rapidly growing offspring.

Once the babies have opened their eyes, grown fur, and have started to show curiosity about grown-up opossum food (like slugs, snails, garbage, and insects) then they may climb out of their mother’s pouch and hitch a ride on her back.

Here, they can observe the tricks of the opossum trade and learn how to find food, hide from predators, and find places to nest. It’s a bit like taking your kid to work for the day. As time goes on the babies will begin to put paws to the ground and wander away from their mom to explore, but they will soon come hurrying back.

How Long Do Baby Opossums Stay With Mom?

Baby opossums are weaned when they are around 3 months old. Weaning is the process where the babies switch from milk as their primary nutrition source to solid food. By 4 to 5 months they make the big step of leaving their mom behind forever and head out into the world as a grown-up.

By this stage, the baby will measure between 7 and 9 inches from their nose to the base of their tail.

Why Do Opossum Moms Carry Her Babies On Her Back?

Opossum babies ride around on their mother’s back for two reasons:

  1. Because they outgrow their pouch and can’t all fit in there anymore. When this happens the babies will work a shift pattern of going into the pouch to drink milk or sleep before swapping with the babies still on mom’s back.
  2. So the babies can learn survival skills. If they spend all of their childhood hidden away in their pouch then they won’t know how to hunt the small bugs, frogs, and bird eggs that they need to eat in adulthood. They also observe how their mum avoids predators and other danger and get to practice finding a safe place to make a nest.

Luckily for mom, this isn’t forever, and the opossum offspring will eventually fall off their mom’s back never to return. When the babies are very young, they can easily hang onto mom’s back – but as they get bigger and heavier and begin falling off this signals the natural point that they are ready to take on the world for themselves.

Do Momma Opossums Sometimes Abandon Her Babies?

One of the problems that come with having up to 8 growing babies on your back is that they sometimes fall off. If this happens, and the opossum baby is too young to survive on its own, the baby will make sneezing sounds that indicate to mom that someone is missing. She will make her ‘ch ch ch’ noise to let her baby know she’s coming back for them.

However, once the babies are big enough to survive on their own the mom won’t come back for them even if they do call out to her. She knows that her chance of survival, and the survival of the rest of her smaller babies, is better with one less baby to worry about.

When Is An Opossum Fully Grown?

Baby opossums are fully weaned by about 3 months old. This means that they no longer rely on their mother’s milk for sustenance and could, in theory, survive on their own. However, most babies stick around for a little longer eventually making their own way into the world by 5 months.

At this point, they will measure between 7 and 9 inches long (not including the tail). In another couple of months, they reach sexual maturity and will be ready to start an opossum family of their own.

What Should I Do If I Find A Baby Opossum In My Yard?

This all depends on how old the baby opossum is. If its eyes are open and it just looks like a smaller opossum, then it will probably be alright on its own so leave it be. Even smaller opossums weighing just over half a pound can survive on their own without help from mom. Make sure there are no cats or dogs around and give it some space.

An opossum is too young to survive on its own if it measures less than 7 inches long (excluding the tail) and weighs less than half a pound. Another dead giveaway of a super juvenile opossum is its eyes – if they are still closed, then the baby is definitely too young to be alone without its mom so you need to take action.

The first thing you should do in this scenario is to look around for the mother. If you can’t see her, then listen for her ‘ch ch’ sound. If you hear her, then back away and give her time to come back for her baby. If there is no sign of the mom, then you will need to contact a wildlife rehabilitation center to come and collect the baby opossum.

Do not try to feed a baby opossum! They have a very particular diet and you could make them sick. If mom isn’t there to help you, then it’s time for the pros at a wildlife center.