Stings from tiny caterpillars have sent children in North Carolina and Virginia to the hospital and encounters are being reported elsewhere in the Southeast.

The Puss Caterpillar — the Megalopyge opercularis — is the most poisonous caterpillar in the United States, according to WebMD.com. The caterpillar’s poison is hidden in hollow spines among the hairs, according to the website.

Silena Lane told WECT-TV that her 4-year-old son was stung by the fuzzy fiend earlier this week in Boiling Spring Lakes, N.C.

“My son cried for two straight hours from the pain, so I hope no one else has an encounter with one,” Lane told the TV station.

In Virginia, 2-year-old Chloe Hicks was sitting on the deck with her mom when he hand ever so slightly touched the bug. The incident sent the child to the emergency room.

“She was screaming bloody murder,” said Melissa Hicks, the girl’s mother. “By the time I got to the emergency room, the rash had spread up her forearm and was heading up towards her shoulder.”

The little creatures make their home in trees. They can be found along the East Coast, from New Jersey to Florida.

“If you touch their fur, or their spines and hair, you can actually get the little barbs stuck in your skin and that pressure on that gland will release a little bit of the venom,” Dr. Elenor Kurtz said.

Generally, you get an instant reaction that feels like a sting from a wasp or a bee. It causes redness, swelling and can spread up the arm. The sensation lasts about 20 to 30 minutes.

A day after her horrific encounter with the puss caterpillar, a red mark was left on Chloe Hicks’ hand.

CNN contributed to this report.