The army worms or tent caterpillars of May 19 had dispersed in the morning but returned to my house at night, this time to the kitchen. They crept up walls and cabinets, through the red-pepper barrier beneath the door, and squashing them left and right I thought I'd go mad, using up paper towels and tissues, finally bringing out the vacuum, harassed, disgusted. Worse than ants. There is nothing in this house for caterpillars to eat, no plants, no breadcrumbs.
But there were none in the guest room although last night they were there by the hundreds; only in the kitchen. Their doors are only a few feet apart. Why were they choosing only the kitchen this evening? (Want to see them crawl? Video, 35 seconds.)
Answer: Light. The guest room was dark tonight but the kitchen was lit. Army worms are caterpillars, soon to become moths, and moths are attracted by light. It must be that caterpillars are, also.
I shut off the kitchen light. Their numbers diminished. I doused all lights in the house but one. Their numbers diminished.
Searching the Net (briefly, because in a minute I'm going to bed and turning out all the lights) I couldn't find this conclusion anywhere else but in a book published in 1896 by the Massachusetts State Board of Agriculture. But I'm telling you: Caterpillars invading your house at night? Shut off the lights!