My crass mass frass class

Are we sitting up straight, class? See the hairy, crawly mass?

The caterpillars march nose to bottom in lines en masse.

The hairs can really hurt you, so let them pass.

The caterpillars chomp leaves and leave lumps of frass. Frass is caterpillar plop, but plop is crass.

Now on your tablets or laptops enter Bag-shelter Moth (Ochrogaster lunifer) and learn more.