All bats do NOT have rabies.
It is a myth that all bats have rabies. Though bats can contract rabies, they are no more susceptible to the disease than any other wild animal.
The highest incidence of rabies is claimed to be the vampire bats indigenous to South America. In the United States, the incidence of rabies in bats has been placed at a fraction of a percent. A higher incidence of rabies has been reported in skunks and foxes rather than bats. As with any wild animal, you can’t tell if they are infected with rabies so you should never handle a bat. 
Rabies in Humans Is Rare
Because most people are aware of the dangers of rabies when bitten by an animal, bite victims generally seek medical attention immediately where a rabies vaccination is administered. Due to this rapid preventative intervention, the incidence of rabies in humans in the United States is rare. According to the Centers for Disease Control (CDC) in a nine-year period between 1997-2006 there were only 19 cases of naturally acquired rabies in the US. 
Why Bats Are Blamed for Rabies
Bats may have become synonymous with rabies because 17 of the 19 cases of human rabies in the United States were derived from bats. It is unclear why this particular percentage is so high but it could be speculated that a bat bite may not be as obvious as a bite from another animal. In several cases, the person bitten by the bat was asleep and likely not aware they were bitten, which is why they did not seek preventative medical attention. 
”Encyclopedia Smithsonian: Bat Facts.” Smithsonian. N.p., n.d. Web. 14 Nov. 2011. <http://www.si.edu/Encyclopedia_SI/nmnh/batfacts.htm>
”CDC – Bats and Rabies – Rabies.” Centers for Disease Control and Prevention. N.p., n.d. Web. 14 Nov. 2011. http://www.cdc.gov/rabies/bats/index.html
”CDC – Bats: Learning about bats and rabies – Rabies.” Centers for Disease Control and Prevention. N.p., n.d. Web. 21 Sept. 2012. http://www.cdc.gov/rabies/bats/education/index.html