Well, gee, be careful not to provide any elaborate information - we might actually be able to help!

most likely rodents. you need to get rid of them with glue traps/cages/srping traps/whatever means necessary. in extreme infestations you may even have to open the walls, but that is rare.

i would tell you to use poison, but be careful cause if they die in there the stink will be bad for a few days to weeks.

once they are gone, plug all holes in teh exterior wall, under the crawlspace, and in the attic. if the hole is large enough for your pinky to fit in it, then a mouse can squeeze thru.

In theory poisons are supposed to dry out the corpses so they don't smell, also the critters are supposed to seek water so they leave the building.

Poisons are arguably cruel and can be dangerous, especially if you have pets that might potentially eat the poisoned corpses.

Glue traps are regarded as incredibly cruel, critters have been known to pull limbs off to get out. The good old fashioned spring trap is best, but if you are not seeing the critters in the house, then you need to work out how they are getting into the walls, and put traps nearby.

One of the best baits for traps I've found is salami, tied on with thread so they can't lift it off. It doesn't spoil, has a strong smell which will attract them and keeps working for ages.

In theory poisons are supposed to dry out the corpses so they don't smell, also the critters are supposed to seek water so they leave the building.

yeah, my FIL put out some poison before coming to our house for 2 weeks. when i took him home last Saturday the house STUNK. sure enough, there were 2 dead mice in his bedroom, just a foot from teh poison and near the toilet. no they were not dried out at all. decomp takes the same course no matter if it is poison, trap, or natural death.

I used glue traps when we had mice. It was AWFUL. The poor things get their feet & tails stuck to the trap, and then DH had to take them out and hit them with a shovel to kill them - put them out of their misery. One poor guy had his NOSE stuck in the glue. We got 2 cats & that took care of the mice problem - haven't seen once since.

I think glue traps are indeed cruel. They have yet to invent anything significantly better than a good ol' mousetrap, they are pretty quick as far as I can tell. If at all possible, try them first.

Salami as bait I've found is best, tie it on with thread. The smell of it helps cover up the human smell on the trap.

The glue traps really are awful - but it can be quite difficult to figure out something to use if there are small children in the house. We eventually used the glue traps, but only in the garage - figuring that if one of the kids got ahold of that, the damage would be less than a potentially broken finger from a normal mousetrap.

Thankfully, after we caught about three that way, it seems they've all gone. Not sure what we'd use in the future if they came back!

Best thing to do with the glue traps when they get mice on them is drop them into a bucket of water. No bashing required, it's quick and fairly painless. I don't like the glue traps though, we use spring traps on the rare occasions that we have a mouse.

Ours used to get into the attic through a joint in the garage ceiling that was sloppily put together. Once we got that sealed up and put some traps in the garage, it's rare to hear the night time scratching.