Leafcutter Ants Decorate Nest with Flower Petals in Tucson

My daughter saw an anthill surrounded by purple and yellow flower petals in Tucson. Do they eat them or decorate?

Leafcutter Ant Behavior

According to Pima County Extension, these are leafcutter ants. They line underground nests with leaves and petals; excess debris litters the surface. They don't "decorate"—it's nest lining material.

See: Leafcutter Ants