Nevada state entomologist Jeff Knight told reporters on Thursday the number of adult pallid-winged grasshoppers traveling north to central Nevada is unusual but not unprecedented and they pose no danger.
Knight says the insects don't carry disease, don't bite, and probably won't damage anybody's yard before they're gone in several weeks.
He says they're usually attracted to ultraviolet light sources.
Knight recalls several similar migrations in his more than 30 years at the state Department of Agriculture, including one about six or seven years ago.
This year, the Las Vegas area recorded more rain in six months than the annual average of just under 4.2 inches per year.