Something for weather geeks:

“Roost rings” showing up on radar around sunrise. What are they exactly? See: http://t.co/AfGVyr2HP6 pic.twitter.com/vzOhGpgGCx

— NWS Wilmington OH (@NWSILN) August 6, 2014

Just before sunrise on numerous mornings since mid-July, a curious doughnut pattern has appeared over several locations on NWS Wilmington, OH Doppler radar imagery. This feature, known as a “roost ring,” occurs when the radar beam detects thousands of birds simultaneously taking off from their roosting site around dawn to forage for insects.

more at the link.