Vesper bats are the common bats we see flying at dusk in Arizona. They are insectivores that use echolocation to hunt. It is quite common for these bats too cause unsightly staining from fecal matter and urine on houses in overhang area’s. Bats are protected here in Arizona and are considered beneficial. Deterring them from an area is the only method of control allowed by the Arizona Game and Fish. You can try mechanical, electrical and liquid deterrent I have had limited success with all. Mechanical is physically sealing the area from bat entry. This is sometimes extremely difficult to do and can be expensive but if done correctly is the most effective. Electrical is the use noise emitting devices that disrupted the bats from flying to an area. I have used these with some success but some people find the noise emitted disturbing. Liquid is by spraying a product like Liquid fence in the area bats are landing it seems to work good for short term but smells bad during application and needs to be applied frequently. Please check out the pictures of some common Arizona bats and the staining they can cause.