SEX RATIOS 
The sex ratio of both species was approximately 1:1 as recorded 
for M, major (784 males, 808 females), and for M, rufus (150 males 
and 189 females). 7 
BREEDING CYCLES 
Evidence was accumulated to indicate the following possible 
breeding cycle in M. major. Pregnant females were taken in June, 
July and August; single, very young bats and lactating females in 
July, August, September and October; and immature males and females 
in October, The gestation period is unknown for this species but 
these observations suggest that there is only one generation per year. 
From these and other observations on this species, it would appear 
that the young are not born before July. This is supported by data 
in Table V, which show a marked increase in the bat population for 
the period June to December, 1959, The same populations remained 
fairly static from January to June, 1959, 
As shown above, the numbers of M. rufus were not sufficient 
to give a clear picture of its breeding cycle. However, pregnant 
females were taken in March, July, August and October; single, very 
young bats in July and October: and immature males in September, 
October and November, From these collections and other observations 
in Trinidad, it is possible that there may be two generations per 
year for this species. 
OBSERVATIONS ON BAT BEHAVIOR 
The bats were generally observed to have two avenues of entry, 
under the roof corrugations and through the louvres, During the day 
they rested in places most inaccessible to humans, such as under and 
between the rafters, also particularly close to the eaves, hiding in 
the corrugation spaces, After flight and during the night when the 
bats returned to the house, they usually clung to the supporting 
rafters and dropped their chewed-up insect foe, feces and urine onto 
the ceiling sheets. They then crawled over the floor to their actual 
sleeping roosts. It is this movement which accounts for the bumping 
and thumping sounds usually mistaken for the presence of rats and 
mice, Thus it was important to place any chemical residue in such 
a position that crawling bats would pick it up on their fur where it 
could be ingested during the preening and grooming process and where 
the toxic fumes would serve as a repellent to the bats. 
