Abstract
The distribution of fed mosquitoes in a village in the Gambia where bed nets are widely used was studied. A total of 3470 blood-meals from Anopheles gambiae Giles s.s. and other mosquitoes was analysed to determine the human blood index (HBI). A. gambiae s.s. collected within nets gave an index of 0·99, whereas those within houses but outside nets gave an index of 0·70. The importance of distinguishing biotopes when presenting HBI values is stressed. By using a unique host, mosquitoes were ‘ marked ’ (with a blood-meal) and their dispersion was studied. Evidence was obtained for movement from house to house and from outside into houses before resting.