Astro tick

An astro tick is, presumably, a form of Cybertronic wildlife.

Fiction

Generation 1

Ironhide once compared the local number of Decepticons to the density of astro ticks found on Ravage's aft portion. G.I. Joe vs. the Transformers issue 5

Ironhide's simile seems to indicate he believes Ravage is a dog. It's a common misconception.