It's a lot like defeating earseekers. Torch the bodies. Search for treasure afterwards. This also works for scorpions and other poisonous crawlies.
You might want to prod the corpses with a ten-foot pole to check for paper (scrolls) in bags or pouches -- presumably, you will hear a crinkly noise -- before torching the corpse. If there's a backpack, torch the corpse a little bit, watch for critters to emerge, then douse the flames and remove the pack. Like the earseeker, it's all about observation -- and about a GM running an observation-focused game instead of a monster slauughterfest.