Hopefully,
We train children not to go near or touch a hot stove.
We train children not to play in traffic and how to cross the street safely.
We train children not to play roughly or bite other children.
We train children to be respectful to their playmates, teachers, relatives and policemen.

Why can't we train them how to behave with animals?

It's a matter of safety for THEM - if YOU don't train your child how to behave in any of the above situations - who is at fault? It's not the child.
Signature line > "You can't fix stupid"