The silver-haired bat, _Lasconycteris noctivagans_ (Le Conte), is a medium sized bat with dark brown or blackish coloration above and below. Many hairs on the back and underparts are tipped with white, with the white tips most numerous on the middle of the back. The wings are dark brown. This bat occurs on the North American Continent north of Mexico, ranging from the Pacific to the Atlantic. There is as yet no evidence that this bat actually stays within the park for any length of time. It is believed that it only moves through during migration. Records thus far obtained are during September, at elevations around 5,000 feet. The Townsend lump-nosed bat, _Corynorhinus rafinesque townsendii_ (Cooper), is of medium size, with long thin ears and two prominent lumps on either side of the nose. The coloration is dark brown above, somewhat lighter below, the base of the fur is dark slaty. The ears, feet and wings are dark brown. The Townsend lump-nosed bat occurs from southern British Columbia southward through most of Washington and Oregon, and along the coast into California as far south as San Francisco. Only one record has been obtained from the park, a specimen collected at Longmire in September, 1937. _Specimens in park collection:_ Miller bat, RNP-85; Northwestern long-legged bat, none; silver-haired bat, none; Townsend lump-nosed bat, RNP-93; Longmire Museum, Park Headquarters. The bats are among the most feared and least known of any of our mammals. Many people are afraid to have anything to do with them, and everyone is familiar with the old belief that, given the opportunity, a bat will fly into one’s hair. Yet the bats that are so common in North America are weak and entirely harmless. Far from being harmful to man, they serve a most useful function in destroying various insects. The worst problem the bat presents is the habit some species have of using buildings as a place to sleep. Although possessing a wing-like structure, the bat does not have a wing in the sense that a bird has. The “wing” consists of a much modified hand with very long fingers. This is covered with a thin, but very tough membrane, that enables the animal to fly. The bat’s flight is seemingly aimless, but is actually purposeful. It is during these “drunken flights” that it catches the insects upon which it lives.