Ask-a-Dave's-Gardener: What's eating my Prickly Pear (Road Kill Cactus)?, 2 by Anniepants

Anniepants wrote:
Hi! I'm in Phoenix Arizona - and I've never seen anything like this before, and am unsure what steps to take. A little information: This (usually healthy) roadkill Cactus is in a pot, next to the house - pretty protected (height, fencing) from common desert critters. I've had snails before, but this is new to me. Looks like something is burrowing in, eating as it goes - hopping around. Worms? Ants? We've caught it pretty quick, just not sure what to do. Thank you so much!