Bats are voracious insectivores and may potentially play a role in the control of vector mosquitoes. We analyzed the diets of five bat species in central Thailand and found considerable amounts of mosquitoes in the feces of bats from an urban colony of Taphozous longimanus. Previous studies have shown that bats can have a substantial impact on the abundance of mosquitoes (Reiskind and Wund 2009). However, our field data (unpublished) showed also that there was no correlation between bat feeding activity and Aedes mosquito prevalence. A lack of this correlation could possible be explained by the diurnal character of Aedes mosquitoes. Hence, bats may possibly be more important for the control of nocturnal mosquito species such as Anopheles species which can transmit malaria and Culex species which can transmit the West Nile virus.
You can read more about the diets of bats from central Thailand here.
Reiskind MH & Wund MA (2009) Experimental assessment of the impacts of northern long-eared bats on ovipositing Culex (Diptera: Culicidae) Mosquitoes. Journal of Medical Entomology, 46: 1037–1044.