Pack Rats - found mainly in the American South-West and in Mexico are known for their habit of taking objects they find in houses and leaving something in exchange. They often exchange a piece of cactus or a stone for a coin or anything that takes their fancy.
Don't know if this fits here but it seemed like a good idea to mention them.
I really like rodents too. Rats are beautiful, gentle, clever creatures. Where as Faeries -- the real kind are not nice.
Cheers, Joy