SAN ANTONIO -- Yet another pest is making its way into San Antonio neighborhoods as a result of recent rains. This one has one of the most painful stings in the world.

The Tarantula Hawk is a wasp that gets its name because it kills and lays its eggs inside large spiders.

University of Arizona entomologist Justin Schmidt describes its sting as "blinding, fierce, and shockingly electric," ranking second only to the tropical bullet ant in terms of intensity.

Residents in one Alamo Heights neighborhood say they've been seeing swarms of them every day.

"I've been reading my paper and I've seen them flying all over the place, I didn't know what they were," said one resident, who preferred to remain unidentified.

Texas A&M entomologist Molly Keck said the wasps aren't uncommon in San Antonio, although they're rarely seen in such large numbers. The males, which are completely harmless, feed on the nectar and pollen of some trees. The females, which have large stingers and powerful venom, walk or fly low to the ground, hunting spiders to pull inside their burrowed nests.

She says the rain this season has given them a feeding frenzy.

"As it rains and the ground gets saturated, those ground-dwelling spiders are pushed out of their homes," said Keck.

The wasps are distinctively marked by black bodies with bright orange or blue wings, often edged in black. But Keck says, despite looking menacing, many people don't even know they exist.

They fly silently, and are so docile that they rarely attack.

"You have to want to be stung by them – pick them up or smash them in your hand," said Keck.

Keck said the biggest threat is people stepping on them by accident. Her advice is to wear shoes and, above all, leave them alone.

In the very rare cases people are stung, the pain is not known to have any lasting health effects.