Yikes, bat doodoo where I live can carry deadly virus called Hendra virus which can jump from bats to humans. LOTS of bats here. We call them flying foxes if they're the same ones you mean. Fruit bats. I do not touch bat doodoo.
Neem oil is great for keeping mozzies away.
Neem trees or shrubs are even better if you can put a couple in the yard.
It's a natural repellant. I guess it depends on your climate. I think they originated in India so might not do well in some of your climates up and over there.
My trick is to take lots of B Vitamins. I swear it works. They don't like me much. LOL Seem to bite everyone else but me, but then again I grew up in the tropics and I'm probably pretty immune. Mozzies are shocking this year and we have Ross River Fever and Dengue Fever all over the state. It's really bad.