That colorful caterpillar in your garden may look cute and fuzzy, but steer clear! Some of the most striking-looking caterpillars have bodies covered with sharp hairs or spines connected to a poison gland under the insect’s skin. Although these hairs are used as defense against predators, you’ll suffer, too, if your skin comes into contact with them.

However, the term “stinging” is a bit of a misnomer. “Stinging caterpillars actually aren’t stinging you and injecting venom, like a wasp would,” says Eric Benson, PhD, professor emeritus and extension entomologist with Clemson University. “When you pick one up or accidentally brush against one, the hairs break off and cause a reaction, such as redness, a rash, and a burning sensation.”

Stinging caterpillars are found on many different trees, such as oaks, elms, apples, and ornamental trees and shrubs, such as crepe myrtles, spirea, and dogwoods. “But stinging caterpillars often do not have a big enough population to be considered plant pests,” says Rafia Khan, PhD, assistant professor and extension entomologist at Texas A&M AgriLife Research and Extension Center. “The biggest issue is their risk to gardeners, who pick one up or accidentally touch it. Kids and pets also can be affected.”

Types Of Stinging Caterpillars

These caterpillars, which are the larval stages of moths, have one or two generations per year.

You’ll see them from spring to fall before they transform into non-descript brown moths. There are many different species of stinging caterpillars, but the most common in the Southeast are:

• Puss caterpillar is one of the most frequently encountered. It’s about an inch long and completely covered with gray or brownish hairs that look soft and fluffy but that hide hollow spines that contain venom.
• Saddleback Caterpillar has a stout, brown body about an inch long with a bright green rectangle and an oval saddle marking on its back. The rectangle and saddle are outlined with white. It has various bumps covered in stinging spines on all sides of its body.
• Hag Moth Caterpillar has bizarre-looking long, twisted appendages on its sides and is about an inch long. Under its short brownish hairs are hollow spines that connect to toxin glands.
• Buck Moth Caterpillar looks mostly black, purple-black or brown-ish with red or orange-ish spots and is about 2 ½ inches long. It’s covered with black stinging spines.

How To Prevent Injury From Stinging Caterpillars

Sometimes you’re minding your own business and you brush up against these caterpillars while mowing or walking through your garden. Accidents do happen, but there are some steps you can take to minimize the risk of coming into contact with these colorful caterpillars. Follow these tips from Benson and Khan:

• Learn to ID stinging caterpillars that are common in your region. Your local university coop extension service (find yours here) can tell you which ones you’ll find in your area.
• Teach kids to never, ever pick up colorful caterpillars. If you find one in areas where kids or pets spend time outdoors, use a stick or garden tool to move it to a remote part of your yard. Like all caterpillars, they’re an important part of the food chain so you don’t need to destroy them, just relocate them.
• Wear gloves and long sleeves when working in the garden in areas where you’ve spotted these caterpillars previously.
• Treat as needed. Most of the time, you won’t need to do anything because they’re often solitary. But if you’re dealing with a large infestation, you may need to take action. Wear gloves to handpick small numbers, then drop into a bucket of soapy water. For large populations, use a product containing spinosad, bifenthrin or Bacillius thurgiensis, according to label instructions.

What To Do If You Get Stung By A Caterpillar

The natural reaction to contact with stinging caterpillar is to rub the area, but that can make the reaction worse because the hairs stick. “The first thing to do is lift the hairs off immediately by using tweezers or a piece of adhesive tape,” says Khan.

Wash the area with soap and water to remove any remaining toxin. Apply a cold compress, and consider taking an antihistamine to help with itching. A dab of hydrocortisone cream also may help relieve discomfort. However, if you have any concerns or have a more severe reaction (such as nausea or difficulty breathing), get medical care immediately. Kids and older adults sometimes have more intense reactions.

Pets who have an encounter with stinging caterpillars will need a vet visit ASAP. “It’s easy for pets to make contact with the hairs, especially dogs who are sniffing them,” says Benson.