Long-tailed Myotis bats are found in Fujian Province. Allen (1923) named the specimen from Fujian, and Ognev (1927) named the specimen from eastern Siberia <M. longicaudatus> according to the characteristics of tail length slightly exceeding body length. Ellerman & Morrison-Scott et al. (1951) listed the latter as a subspecies of the long-tailed Myotis bat.
The echolocation call made by long-tailed myotis bats in flight is of the short-FM type. The call consists of three harmonics, of which the first harmonic is the strongest and occurs in all calls, starting at 110.8 kHz and ending at 50.2 kHz for 3.5 ms. The second and third harmonics are weaker, appearing in 50.0% and 25.0% calls respectively, and the frequency range is 138.4-116.6 and 193.6-170.8kHz. Based on the characteristics of echolocation calls, it is inferred that long-tailed Myotis bats prey on ground insects in a complex environment.