Giving birth is one of the most difficult experiences that animals will go through in their lifetime and although all animals share the struggle, no two creatures experience the same journey. Take elephants and humans for example, we’re both mammals despite an obvious size difference and while human pregnancies last approximately 9 months, an elephant’s is about 22 months – almost 2 years! There are some which are even more surprising. Let’s take a look at how some animals make their way into the world. 

1. Mammal Born from Eggs

We’ve all been taught that a key feature of mammals is that they deliver live young, but it turns out that there are some exceptions to the rule. There’s a small group of mammals, known as monotremes, who lay eggs and they include the duck-billed platypus and four different kinds of echidna. Unlike reptilian or bird eggs, monotreme eggs are usually small with a leather like shell. After a short period of incubation, the young hatch and are practically helpless, unlike their amphibian counterparts. Some of them spend months inside their mothers’ pouch lapping up milk until they become mature and can live on their own.

2. Mouthbrooders

When it comes to good parenting skills, fish are typically found on the bottom of the list. Why? Because once the eggs are fertilized, they’re often left to fend for themselves. There are a few, however, who will defend their young, and even fewer who do it in a unique way that earned them the title mouthbrooder. This group of fish carry their eggs in their mouths until the time comes for them to hatch and some will even keep their young there for a short time afterward. During this time the father or mother doing the mouthbrooding is unable to feed with some species going over a month without food. They will occasionally let their young out to feed but can signal them back when danger is sensed. 

3. Male Birth

In most animal species where animals carry their eggs within their body, it is usually the mother who is tasked with the job of caring for them. There are some species like the pipefish, seahorse, and leafy sea dragon where the fathers are the ones who ensure that their offspring make it from egg to hatchling. During an intricate and lengthy mating ritual, the female is able to deposit her eggs into her male counterpart’s pouch where they are fertilized. He then swells as upwards of 2,500 eggs develop in his pouch. When they hatch, the male uses muscular contractions to eject them into the ocean. 

4. Eating Your Siblings

Survival of the fittest is a term that is commonly used but has great meaning for many animals. It’s one thing to have bigger, bad animals hunting you down, but when it’s your own family who is after you, it gives the saying more importance. Sand tiger sharks sometimes start with many fertilized eggs (up to 12) but oftentimes, much less will emerge… and that is because of intrauterine cannibalism. Once the eggs hatch, the largest shark often eats their brothers and sisters on their side of the uterus. Although it sounds terrible, this gives young tiger sharks the best chance at surviving on their own. 

5. Darwin’s Monsters

Parasitic wasps are common, and they often target invertebrates as their main food source, but they also take things a bit further. Some of these wasps hunt down their prey, sometimes using paralysis and lay eggs in their prey (who are still alive). The larvae will then slowly devour their host. Some larvae are able to release chemicals that control the minds of their host which further helps them to survive. Darwin wasps are examples of animals who employ this method to ensure the survival of their species.