Trimothy

"Found in great numbers near expansive, open grasslands, and tightly packed human settlements. These creatures have a ritualistic 'coming of age' ceremony, where they migrate away from their families in great numbers - usually on weekends, specifically in the morning."
Ah yes, the soothing scent of freshly cut lawn. Make sure you control the migration path of these guys, directing them to your compost or green bin, rather than let them float out into the great beyond.