This triptych shows the tent caterpillar egg mass on the left, followed by the caterpillars in their web or 'tent', and the 'tent' itself, with a weight of frass (insect poop) at the very bottom. This was on a choke cherry tree. Black-billed and yellow-billed cuckoos find these caterpillars a treat, and in years when the tent caterpillars are high, so we see more cuckoos. This photo was taken in the Burnt Lands Provincial Park.