mean more or less the same
They mean exactly the same, but zemrzeć is appropriate only for humans.
Germans too, I believe, callsa animal mouth a Maul and a human one a Mund.
Polish too: morda - animal, usta - human. Although as an insult people say: Zamknij mordę. (Shut your yap!)
Same with to eat: with animals it's żreć with people - jeść.
An animal has a łeb, a person -- a głowa.
with a link
There is life beyond links. Not everybody is chained to e-gadgetry. People hear things at work, at parties, on trains and buses and in shops, see headlines at news agent's, etc., etc. On more than one occasion I have heard things the lines of "dogs are also people", admittedly not in Poland. "Pies to też człowiek" sounds ridiculoius in the tongue of Mickiewicz and Słowacki. In view of the dog beauty parlours, hotels, clothing shops, cemeteries, etc., there must be people that actually believe it and are willing to fork over their hard-earned cash to prove it.