It's a sad state of affairs, but too few parents nowadays bother teaching their children proper respect for other people's belongings (in particular, other people's pets). When I was a child, I was very gentle with my cats and if I was visiting a pet owner (especially if they were babies) I always followed the owner's, or my mother's, instructions to the letter.

What is more saddening than the children's behaviour is the fact that their mother saw the behaviour as normal, even positive! These children simply know no better if they are following the example of an adult with values like that!