In March 1957, an outbreak of human sleeping sickness was discovered in the South Mamprussi District of northern Ghana. Temporary measures were initiated at a few villages to provide protection, at water-holes on streams, against attack by the two prevalent species of tsetse, Glossina palpalis (R.-D.) and G. tachinoides Westw., until clearings could be made.

These measures consisted of grass-mat passages approximately 8 ft. high, extending from about 75 yd. from the stream down to and around the waterhole. At the water-hole, there was a gap of about 1 ft. between mat and water.These passages were found to be successful in excluding tsetse fly. This suggests several points of interest about G. palpalis and G. tachinoides: that at that time of year and in that type of vegetation, they do not rest higher than 8 ft. above ground; that the portions of human anatomy that showed beneath the matting did not attract the fly; and that these species depend on sight for hunting rather than on smell.

The cost of this matting was negligible as compared with the cost of routine clearing, and this method of temporary protection was considered successful for its purpose.