We have had problems with bats getting into our bimini cover in the past. They can't resist crawling into those small holes where the backstays pass through. We found that it commonly happened when we hadn't used the boat for more than a week and a half. After using it more often, we found the bat moved on to another boat about 50 feet away that was not being used. It's hard to deal with these things sometimes, but I guess it reminds us that Nature will always have the upper hand.