Little Brown Bat

There are few animals that "freak" people out more than bats. But like most things that scare people, the truth is far removed from the perception.

First, let's lay some myths to rest. Yes, there are vampire bats—exactly three species out of more than 1,200 species of bats worldwide. And yes, they do drink blood, but they are far—far—more likely to get it from cattle or other mammals than from you, and rather than sinking long fangs into an unguarded neck, the vampire bat with slice a small section of skin away and lap up the blood, using an enzyme in their saliva to keep the blood from clotting, an enzyme, by the way, that is used to treat stroke victims. Another myth is that bats will fly into your hair and become entangled. Possible, yes. Likely, no. Bats are highly evolved not to run into things, especially not some big, potentially dangerous, slow-moving mammal. Bats are not flying mice. Not even close, other than both are mammals. In fact, bats are actually grouped with primates in the superorder Archonta.

What is true is that bats are incredibly diverse and extremely important. The more than 1,200 bat species make up a fifth of all the mammal species in the world. The minuscule bumblebee bat weighs less than a penny, while the flying foxes (two genuses) of Asia, Australia and numerous islands in the Indian and Pacific Oceans can weigh up to 2.4 pounds and have a wingspan of 5-6 feet. Having been around almost since the age of the dinosaur, bats live almost everywhere, except the polar caps and extremely arid deserts.

More than two thirds of bats eat insects—insects like mosquitos and those that damage crops throughout the world. One of Hanford's most numerous bats—the little brown myotis—typically eats up to 1,000 mosquitos a  night, and if a female and pregnant or nursing, can eat her body weight in insects each night. Most of the remaining bat species feed on fruit or nectar, while about 1% eat frogs, rodents, etc., even fish—fishing bats can snatch fish from the surface of water like an osprey. Then, there are the three vampire bats.

Not only do bats benefit agriculture by eating destructive insects, bats are one of the most important pollinators in the world, especially for certain fruits like mangoes, bananas and guavas. One agricultural species almost solely dependent upon bats is the agave, from which we get tequila. Your call on whether this is important or not. Not only do bats pollinate flowers, they are important in moving the seeds of many of these same plants. Bats eat the fruit and either move the seeds stuck to their fur, or . . . seeds come out the other end.


Now, what about the bats at Hanford?

Silver-haired Bat


Hanford Bats

The Hanford Nuclear Site has proven to be a great location for bats. Found here are the big brown bat, little brown bat, hoary bat, long-legged myotis, pallid bat, silver-haired bat, canyon bat (western pipistrelle), western small-footed myotis, California myotis and Yuma myotis. Also possibly found here, since they are found elsewhere in Washington's shrub-steppe, are fringed myotis and Townsend's big-eared bat. Of these, the western small-footed myotis, pallid bat and canyon bat are at the extreme northern edge of their range. The little brown myotis is likely the most common bat found here.

Basalt cliffs and the abundant riparian area on the Monument are bat hot spots, as are the White Bluffs. But unlike many other areas, on Hanford buildings are important for bat populations. In fact, one area has become somewhat famous within bat circles. About 2,000 Yuma myotis bats live in one of the concrete structures that used to hold water for the F Reactor. The bats roost there from mid-March through mid-October before heading off to hibernacula (a place to hibernate) for the winter—where is a mystery.

Video of the Bats in the F Reactor Water Storage Facility


Other sources of bat information:
        Bat Conservation International (
        Bat World Sanctuary (