Field Observations on the Activity of Pheidole

A method is described for observing the numbers of ants foraging on the surface of of the ground by attracting them to baits of raw meat. The general area is described briefly and sites were selected for the work in three types of country. A total of 50 baits were laid on each site in July and October. Pheidole sculpturata and P. crassinoda were the most abundant ants found on the baits. These were active mainly in the morning and evening, fewer ants were found at midday during the dry season. Comparing the numbers collected on the baits, more Pheidole were found in July than in October, and in July more ants were found on the unburnt grey soil sites than elsewhere. On the red soil sites there was a difference between burnt and unburnt country only in October, when more ants were found on the red soil in unburnt country. Pheidole is compared with three other genera of ants commonly found on the baits. The food of Pheidole is mainly grass seeds ; some reference is made to the supply of grass seeds in different types of country and the relation between this and the numbers of foraging ants.