Those pesky crows just won't leave the quad at Illinois State University.

In its latest attempt at crow crowd control, the university is hanging bright inflatable balls with target-like circles meant to look like the eyes and mouths of predator birds.

But to at least some of the thousands of crows roosting there they evidently just look like harmless globes of yellow, black and white.

ISU grounds staff arborist Heather Wilcox was hanging more "Scare-Eye" bird chasers Friday as three crows flew into a nearby tree.

Still, she says that judging by how often they have to clean sidewalk droppings she thinks the effort that began two weeks ago might be having an effect.

Reports show earlier this winter, staff even tried noisemakers resembling bottle rockets.