I remember sleeping in places that were infested with rats and waking up with one trundling over my face. Actually, I hate rats! In my time, I've picked up all sorts of things in hotels-fleas, lice, tapeworm.
Just recently we were coming out of Niger and it so happened that there was a great pilgrimage so all the hotels were full. We ended up sleeping on the floor in tin huts with bed bugs and fleas.