Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

flat bug

insect
Also known as: Aradidae, fungus bug

flat bug, (family Aradidae), any of about 1,000 species of small, flat, dark-coloured insects (order Heteroptera) that are usually found under stones, in crevices in dead or dying trees, or under loose bark. Nearly all flat bugs range in size from 3 to 11 mm (0.12 to 0.43 inch) and feed on fungi and sap in decaying wood. Their wings, though well developed, remain quite small. Species occur in all zoogeographic regions.

This article was most recently revised and updated by Kara Rogers.