Alright, my husband and I replaced the old basement door, it's good and sealed now. We went through and did some tuckpointing outside and sealed up all cracks and holes down in the basement. The problem is that there are 2 built-in storage units (complete with dry-wall and subflooring) in the corner of the basement. These have been there for about 15 years and I'm sure we've got some cracks and holes there, but we're not ready to demo them yet. We've also sprayed the interior and exterior perimeter of the house with a home defense pesticide in preparation for the colder weather. Last week it got pretty chilly and we began seeing, for the first time since the new door was installed, some more dead crickets in the basement. I assumed either our cat was hunting them, or they were dying from contact with the pesticide (which says is safe around pets once it's dry). This weekend we found a baby garden snake, which was probably who was killing (but not eating?) the crickets. Any ideas on how to prevent more from getting in? Without demo-ing those storage units? Someone said he may have even come up from the drain but I didn't think that was likely. Thoughts?
Oh, this is pretty much what the little guy looked like. Don't worry, we didn't kill him, we just took him outside and let him go at a near-by park in some thick grass.