Lots of mosquitoes here. One thing I know for sure- it's alot easier to kill the larvae than the adult. I collect rainwater for my garden and the mosquito larvae hatch in these collectors. I figure since the mosquitoes are going to lay there eggs somewhere around here anyway, I allow them to hatch in these collectors and then I can kill the larvae and eliminate part of the population. I'm sure it's only a small fraction that I am killing but it makes me feel better anyway. I think bats are the best predator. Purple martins not as much since they generally fly higher than the mosquitoes. At least that's what I have read.