248 The Irish Naturalist. December, 



in stables, cow-houses, and barns. These gatherings are 

 chiefly noticed in summer, and seldom remain more than a 

 few weeks. In two consecutive years, 1898-1899, a space 

 between the woodwork and wall of the farm-stable at Bally- 

 hyland was occupied by a swarm of L,ong-eared Bats during 

 the first fortnight of August, which disappeared soon after the 

 middle of the month. In the second year of their visit (1899) 

 particular pains were taken not to disturb them, but by August 

 20th none remained- In August, 1900, there was a swarm 

 over the doorway of a neighbouring forge, of which not a 

 trace could be found in September ; and in July, 1901, a smaller 

 assemblage took possession, for one or two days only, of a 

 space between two beams in the roof of an old mill. This 

 last-mentioned swarm probably consisted of females, with new- 

 born young ; for an infant specimen, with eyes still unopened, 

 was found on July nth crawling on the floor immediately 

 below the crevice in which the adult Bats were at the time 

 visible. Since these swarms are so much more frequently 

 noticed in July and August than at other seasons ; and since 

 there is also evidence (as in the instance last cited) that they 

 are not composed exclusively of the young of the year, it 

 seems natural to infer that the social instincts of this species 

 are strongest in summer, and that individuals which have 

 lived solitary lives during the rest of the year become, at that 

 season, gregarious. 



The shrill "thin" chirping cry of this bat is somewhat 

 celebrated, owing to the fact that a good many persons, not 

 otherwise deaf, are unable to hear it. It is generally assumed — 

 perhaps with too much confidence — that only the L,ong-eared 

 species possesses this very shrill note. It is uttered both on the 

 wing and at rest, and a young individual, only a few days old, 

 when in captivity used this piercingly shrill but faint cry at 

 frequent intervals, apparently as a sign that it wanted food. On 

 summer nights, we often hear a similar cry from some fixed 

 spot in a tree, repeated at intervals of about a second (or 

 sometimes faster) for many minutes together. This is heard 

 at nearly all hours of the night, and most frequently from 

 about the end of July to the first or second week of September. 

 It probably proceeds from bats of the present species, 

 perhaps from young specimens not sufficiently practised in 

 flight to spend the whole night on the wing. 



