At first glance, they may look harmless. But the fat, furry caterpillars known as puss, or asp, caterpillars come with a warning: their fur is venomous.
"It's the pain. It is instant and immediate, and it's very intense," said Dr. Glenn Hardesty, ER physician at Texas Health Arlington Memorial Hospital.
Hardesty describes the sting from first-hand experience as more painful than the sting of a bee, a jellyfish and even a scorpion.
It can also cause vomiting, convulsions and a drop in blood pressure.
"During certain times of the year, they become more prevalent, and we are in a time of year when they become more prevalent," said Hardesty.
Reports of ER visits from people who've been stung by the caterpillars, which are commonly found in North Texas, are on the rise in Central and East Texas.
Hardesty suggests looking around for them when you're working outdoors, though they are known to fall out of trees.
Also, talk to you children about the dangers, as children are often tempted to pick them up.
Should you come into contact with the caterpillars, the spines, hairs and toxins can be removed with tape. Place the tape over the sting and remove. Use a new piece of tape and repeat several times. After that, flush the area with soap and water. Monitor the sting; should the condition worsen, seek medical attention.