Many Arizonans are surprised by an invasion of yellow caterpillars this summer, and their migration is causing many of the critters to meet their demise on streets, highways and driveways.

The Town of Fountain Hills has received a few calls regarding the caterpillars, according to TOFH Public Information Officer Bo Larsen.

According to scientists reporting in the media the caterpillars are in fact an annual phenomenon, with the staggering numbers this year due to an abundance of food left behind by the monsoon rains.

After feeding largely on weeds and grasses, the caterpillars that survive their migrations form the White Line Sphinx Moths, sometimes called the Hummingbird Moth.

Neither the caterpillars nor the moths pose any danger to people, other than a nuisance that turns up in the pool filter or squashed on the driveway.

It does appear that one way to reduce the presence of the caterpillars in a particular area is to simply remove the weeds that have grown.