TOPEKA (KSNT) – Spotted a fuzzy-looking caterpillar lately? An insect expert says you might want to leave it alone as it could be packing a painful surprise.

27 News spoke with Kansas State University Entomologist Raymond Cloyd about some peculiar-looking caterpillars people might spot as summer turns to fall. Brightly colored and covered in hairy barbs, these insects should be handled with care – or not all.

Cloyd said there are three types of caterpillars people might encounter that could be harmful if picked up. These include the caterpillars of the American dagger moth, the Io moth and saddleback moth.

“They have these hairs that can be irritating and that’s what they use for defense,” Cloyd said. “That’s why when you see one of these caterpillars, its best not to hold them.”

These caterpillars come with their own distinct markings and have barbs or hairs protruding from their bodies which can cause problems for those who come into contact with them. The American dagger moth caterpillar, for example, can cause skin irritation, rashes and possibly allergic reactions, according to K-State.

“These are ones you should just leave alone,” Cloyd said.

Cloyd’s biggest recommendation is to leave the caterpillars be, unless they are becoming a nuisance on local trees or other plants as they feed and prepare to transform into moths. However, with winter on the way, many of these caterpillars will soon run out of food sources and cease to present any issues like this until the following year.

“Any time you see an insect with hairs or structures on it, its best to leave it alone,” Cloyd said. “Just be cautious of what you pick up.”

Close-up of a partially coiled woolly bear caterpillar. (Photo Courtesy/Getty Images)

While these caterpillars may cause issues for people who decide to touch them, there are some which will present no such problems. These include woolly bear caterpillars which are considered harmless despite having some structures which are similar to their feistier relatives.

“The woolly bear caterpillars, you can handle those,” Cloyd said. “There’s just a handful of these caterpillars that if you handle them you could get an irritating feeling.”

Cloyd encourages people who want to learn more about the caterpillars of Kansas to pick up a copy of the “Insects in Kansas” book. You can find a copy by clicking here. The U.S. Department of Agriculture (USDA) also keeps resources on harmful insects online.