Who leaves a mouse on a glue trap until it dies? That's messed up! I can hear when a mouse is on those things and at that point I carry the frightened mouse outside, pour a cap full of vegetable oil around it's feet and it frees itself, running off into the yard, then the trap goes in the trash. Heinously cruel? Only if you're a lazy shit.
Definitely don't use poison. It's not painful for the rodents, but it makes its way up into the food chain. Mountain Lion P47 in CA is alleged to have died from rat poison ingestion.