|  |  | Dragonfly: Amazing Hi-Res Headshot www.flickr.com — Giant dragonflies can glide for 20 meters at 10 degrees and a speed of 74 cm per second, which is similar to some birds. They typically eat mosquitoes, midges and other small insects. They are therefore valued as predators, since they help control populations of harmful insects. Dragonflies do not bite or sting humans.More... (General Sciences) Comments Email Added 2008-06-24 13:41:24 lazycat