frass

mass noun

1. fine, powdery sawdust left by boring insects
2. excrement of insect larvae

1. The telltale holes in the wood, the piles of frass under the furniture, the crowd of termites, yawning and sighing, all led to the deduction that boring insects were at work.

2. "Honey, time to clean out the ant farm - that frass is getting smelly."