Axe murderers & blood suckers, part II

See previous post to get the background. It is now 10:00 p.m. and I have been down to the basement to see the bat that Dale found before he left town. Before I even got down the stairs, I found 2 more bats in addition to the one I trapped under a wastebasket earlier this evening. That means there are at least 4 down there now, 5 yesterday, a total of 9 we've seen in 2 days. How many more can there be?! I think I'll take a sleep-aid tonite! I'll definitely call an exterminator tomorrow.