Years ago I sealed up all the entrances to the crawlspace, but last week I noticed that one had come off. Argh! I wasn't about to just seal it back up because I figured that with the cold weather coming on (Berkeley, CA, not freezing, but quite chilly in the winter), some animal was probably under the house.
I figure before I seal up (this time with a door and latch), I have to get whatever animals out of there. I started by putting some strained dirt over the ground just below the ~18x24" opening, smoothing it carefully to reveal any footprints of an animal going in or out. Next day, sure enough, footprints, maybe about the size of a small cat (but I figure it wouldn't be a cat, but who knows?).
I tried a trick I'd heard of and put an open container with some rocks in it (to keep it from tipping over) with ammonia and a rag, to disperse noxious and offensive fumes, right in back of the opening, so the animal(s) would have to pass the concentrated fumes when going in/out. I figured that after a day or two the animal(s) would find friendlier accommodations. After two or so days of this, footprints are still in evidence.
What can I try to expell the varmint(s)? I figure I can maybe work up a one way door of some kind, but it seems tricky.
Dan