Why do 'hissing cockroches' hiss?

Jayme from the Audubon Insectarium explains why (and how) "hissing cockroaches" make the sounds they do. 
Every Saturday and Sunday through January 9, 2011 visit the 'Harry's Big Adventure Bug Petting Zoo' on the upper level of the Museum of Discovery. (Also visit the Museum of Discovery's permanent bug collection on the lower level.)

Many other hands-on experiences are part of the exhibit

 (and included in your museum admission)

Thanks to our local sponsor