mj wrote:
Besides poison, what are rat traps usually baited with? I know that
mice like chocolate, cheese, peanut butter etc but I assume rats have
their own preferences?

Rats go for chocolate too. IMO it's ideal vermin bait, lasts a long
time, smells strongly, difficult for them to prise off the trap so they
are guaranteed to set the trap off trying to pull it off the peg.