The abundance of the Mexican bat in some favorable places is almost incredible. At Tucson, Arizona, I once saw them, a short time before dark, issuing from a small window in the gable of a church in such numbers that in the half light they gave the appearance of smoke pouring out of the opening. At times they occupy houses in such numbers that their presence and accompanying offensive odor render the places uninhabitable. At the town of Patzcuaro, near the southern end of the Mexican table-land, I saw two rooms in an old adobe house occupied by as many of them as could possibly hang from the rough ceiling. The owner considered their presence a valuable asset, as he collected and sold the guano for more than the rooms would have brought in rent. The bats congregate in even greater numbers in large caves. So numerous are they in certain caves in Texas that the owner reports an annual income of about $7,000 from the guano. They are very plentiful by day in the thin crevices about the roof and walls of caves in the celebrated Ixtapalapa, or “Hill of the Star,” beyond the floating gardens at the City of Mexico, and I also found them living in many of the marvelous ruins of Mexico, including Chichen-Itza, in Yucatan. Wherever they occur in numbers they may be heard frequently by day shuffling uneasily about and squeaking shrilly at one another. [Illustration: BADGER The huge fore claws are a strong feature. The hind claws rarely show in the track. The broad spread of the tracks in the lower trail corresponds with the low, thick form of the animal.] When they first come out after sunset they usually fly away in a great stream, nearly all in the same direction, as though migrating. This course will probably be found leading to water, where they scoop up a drink from the surface before beginning their wonderfully erratic zigzags through the air in pursuit of insects. From the colder northern parts of their range they migrate southward to milder climatic conditions or descend to lower altitudes. In Mexico, where they live up to above 8,000 feet altitude, they move down from one to two thousand feet. Their young, one at a birth, are born from April to May. It has been claimed that the Mexican bat brings bedbugs to infest houses. This is untrue of this or any other bat. These animals have certain small parasites, some of which, resembling small bedbugs, have probably given rise to the belief mentioned. These parasites live only on the bats. [Illustration: THE TRACK OF A BIG BULL MOOSE WALKING ON HARD GROUND