If you own a pet, you may have referred to them as your "furbaby." Although they're a lot hairier than normal babies (and use the washroom differently), you look after them in ways that are similar to taking care of a child.
You feed them, give them love and affection, and care for them when they're sick. You also clean up after their furballs, although that's a chore we wish to forget.
If you have actual children, they may also get involved in looking after the animals.
This is what led to the viral video of an adorable little girl treating her cat like a baby. Nothing but pure joy exists beyond this sentence!