I'm probably being ridiculous but...
The other day we were leaving the house and there was a spider outside our door. DS (20 mo) saw it and immediately stamped on it and killed it. I was surprised and a little bit upset tbh - I'm not a big fan on spiders but don't believe in killing any creatures unnecessarily and although I know he's probably too young to get it I told him that we don't stamp on insects on purpose.
AIBU to think this is learned behaviour, and not just something he randomly did? He never stamps on anything usually (except puddles).