According to an article on BBC' website at http://www.bbc.co.uk/news/technology-20080389 a honey bee can bite with a chemical that stuns the victim. They appear to use this bite against small pests such as the Varroa mite and Wax moth larvae.
"Honey-bees are known for their sting, but scientists have now discovered they can also bite.
Bees resort to biting when faced with pests, such as parasitic mites, that are too small to sting.
Close study of the biting behaviour has revealed that they secrete a chemical in their bite that stuns pests so they are easier to eject from a colony.
The pests that honey-bees bite include varroa mites as well as wax moth larvae."