circles on underwear, skivvies or other pantswear that show up and may be the work of aliens (such as Klingons or other off-world groups)
Mikey noticed that every morning when changing his underwear his dog Lucky would immediately start licking the mysterious crap circles that had appeared there.
The swirl designs that are left behind in the toilet after a hefty poop.
"Jesus! Who left all these crap circles? And when did we have corn?"