Killing in itself is bad. So.... who would ever answer no to this question?

Cats and dogs are cute but cats require much less care and attention.

No, it should not be legal to have sex with dogs because they can't give consent.

Fish laid eggs long before chickens even existed. Therefor eggs came first.

Sometimes it's better for an abusive parent to leave and not come back.

I mean, why not? They're not hurting anyone and it'll improve their happiness. Also they'll feel less excluded from the rest of society.