National Weather Service radar picked up something besides rain on Tuesday.

Observers say what looked like massive areas of precipitation on the radar in Ohio, Pennsylvania and Indiana, were actually migrating swarms of dragonflies mixed with other insects and birds.

Lake Erie beaches seem to act as swarming areas for migratory dragonflies, which often gather along them in late summer and fall, according to the Ohio Department of Natural Resources.

ODNR has recorded 164 species of dragonflies in the state which they say are excellent indicators of water quality and serve as barometers of the health of streams, lakes, and wetlands.

Depending upon the species, adult dragonflies may only live for a few weeks to a few months.

The adults exist primarily to reproduce and serve important ecological roles as predators of small insects, especially mosquitoes.