Concord, Mass.
1907
May -
  The Bats began to return to our wood shed loft at
the farm early in May. They appeared there on the . There
were  on the  on the  on the .
Bats in our wood shed loft.
  They pass the day clinging to the rough boards in the peak
of the roof in a closely impacted bunch or cluster. Directly
beneath them is a carpenters' bench where I have had 
men at work much of the time. No amount of
noise or of sudden movement disturbs the Bats in the
least. We shingled the inner wall of the shed one
day working up to within two feet of the cluster of Bats
& pounding vigorously but not one of them moved. When
the weather is warm they sometimes separate into two
or three clusters or even scatter about singly and
occasionally when there are several successive hot days
they all disappear returning with the first change
to cooler weather. At evening they leave the shed
singly at short intervals just as it is getting dark.
Rising above the trees they course about for a minute
or two and then fly off in every direction, singly.
I have hitherto supposed that they stayed out all
night but early in June Gilbert found one of them
clinging to the roof of the shed about 9 P.M. and
the next evening at 10 P.M. there were six of them
there. On this second occasion Gilbert had examined
the shed and made sure there were none there about
an hour before he found the six so these must have
gone out and come back again. Both nights were
clear but there was no moon.