"Those children love animals."
Translation:Tamte dzieci kochają zwierzęta.
Well, you don't know, maybe there are only girls among those particular children :P But you're right. The grammatical gender is important here, the fact that the word is neuter. So even if those children are actually boys-only, if you decided to say 'children' and not 'boys', they're not masculine-personal.
There are very few neuter words that describe people... actually the only other word that I can think of right now is "niemowlę" (baby, infant - one that doesn't talk yet).