Frass

One early summer day in 1981 when I was standing at the back of our house, with the sun shining brightly and nothing but warmth filling the air, I noticed a sound like light rain falling.  The pitter-patter was especially loud under a young oak tree by the basement door, and eventually I realized that what I was hearing had some relation to the thick litter of tiny black droppings on the ground under the tree.  Gypsy moth caterpillar infestation! 

That summer, like millions of other New Englanders, I was made sharply aware of these voracious pests, and of a word, new to me, for their noisy droppings: “frass. 

Frass is the excrement of larvae, or the refuse left by boring insects.  The term is traced by the OED back to the scientific papers of Victorian entomologists, who devised a whole set of splendidly grandiloquent paraphrases for insect droppings: “excrementitious matter,” “rejectamenta.”  The word “frass” itself derives from a Germanic root meaning “to devour,” and nowadays Germans use the term to signify “swill” or “muck,” whereas for insects’ excrementitious matter they say Frassmehl.   Interestingly, in modern German there are different verbs for the kind of eating that people do (essen) and that animals do (fressen).  If you want to insult someone German for eating like a pig (or a caterpillar), just say to him “du frisst.”  I read once of some courageous anti-Nazi who found exactly the right insulting term for Hitler, especially Hitler during one of the not infrequent rages when he ranted and raved and fell down grotesquely to the floor, foaming at the mouth.  Teppichfresser, he called the Führer: “carpet gobbler.”

Once upon a time in English we made the same distinction as in German between human and animal eating, using etan for the first activity and fretan for the second.  Over the centuries the ancient verb fretan has become the word “fret,” in the sense “to gnaw or eat away.”  When you fret over something you are being nibbled by worry.  Little bites are being taken of you, as if you were an oak leaf at the mercy of hungry gypsy moth caterpillars.  Fretting was unquestionably what I did through that summer of 1981, as the sound of larval chewing and of droppings bouncing down from branch to denuded branch blended together in a wearisome duet, and I wondered if our oak tree would survive.  It did, but with time the caterpillars are certain to return in a swarm.  That’s cause enough to fret about our vulnerable forests, not to mention all the frass that might befall.