My neighbor was asking me where is Purple Martins had gone, and said he thought there were now more mosquitoes around. Despite comments to the contrary, Purple Martins do not eat thousands of mosquitoes. On the other hand, bats do. You can have success in attracting bats by putting up a bat house.
A few reports of West Nile Virus are starting to show up in Texas. You will not catch West Nile Virus from cleaning your feeder, or washing a birdbath, but it is a very good idea to make sure the water in your birdbath is changed every 3 days or so, so the mosquito larvae will not have time to develop.
The Bat Conservation Network has information for bat houses.
http://www.batcon.org
The CDC has info on the latest WNV reports.
http://www.cdc.gov/ncidod/dvbid/westnil ... tailed.htm