See the context of this sign.

Brine Flies

"There is a fly which looks something like our house fly.... Any
time you can see there a belt of flies and inch deep and six feet
wide, and this extends clear around the lake.
Mark Twain, 1872

If only all flies were as nice as Mono Lake's brine fly, they will not
bite, bother, or even land on humans. They begin their lives in
Mono Lake as eggs, then mature to larvae and the cocoon like
pupae. The birds eat both larvae and adults. The Kuzedika Paiute
indians used to gather the pupae, dry them, rub the shell off, and
boil them into mush or add them to other food. The incredible
numbers of flies seen by the Indians and Twain have not occurred
in recent years.

Don't miss the rest of our virtual tour of Mono County in 1242 images.