We have bats. This is a good thing -- messy, but good. Bats are wonderful for the garden and for pest control. The Little Brown Bats that live in our front porch eaves eat insects. One bat can eat 600 mosquitoes in an hour. They are only 3 inches long so they are very compact munching machines. I figure they are helping the garden and the horses - no mosquitoes, no West Nile Virus.
Unfortunately, their night roost area is in the eaves of the front porch right next to the front door.
They've been using the same spot for a few years now. The crevice they crowd into is small and we never would have found them if they hadn't left evidence below.
The covered porch runs the length of the front of the house. This helps keep the south facing house cool in the summer. Down at the far end of the porch, outside our bedroom, we have a sitting area with a couch and a couple chairs. It's a wonderful place to relax and read a book. Apparently, it's also the dining room for the bats.