Overall, one thing’s clear, humans aren't the only one who has it rough when it comes to giving birth. What’s the craziest animal fact you know? Tell us in the comments. And thanks for watching.

Overall, one thing's clear, humans aren't the only one who has it rough when it comes to giving birth. What's the craziest animal fact you know? Tell us in the comments. And thanks for watching.

Narrator: Scientists have studied a lot of pregnant animals in space ... there's a good chance that one day humans will give birth somewhere beyond Earth, and that brings up some interesting ...

New research suggests that twins were actually the norm much further back in primate evolution, rather than an unusual ...