Host Decoy Traps (HDT)\u00a0sample outdoor-biting mosquitoes and have potential as a monitoring malaria vectors. The trap emits human odour, is visually conspicuous and heated to human body temperature, thus mimicking a human host, and therefore, it catches a proportion of the number of mosquitoes that would land on a host with the same characteristics. For example, at low population densities of Anopheles coluzzii, the HDT\u00a0can catch 1.5x that of a standard human landing catch, and in the rainy season this increased dramatically; the HDT can catch 10x the number in a human landing catch.The trap consists of an adhesive trapping unit and an odour source. Human odour from a volunteer in a tent is blown down the plastic pipe and around the warm visually conspicuous trap. Mosquitoes are attracted to the odour. The high visual contrast of the black trap against the soil is seen by mosquitoes and they fly close to the trap to determine if it is the host. At close range, mosquitoes detect the relative warmth of the trap compared to the ambient air temperature and this induces landing in search of a suspected host, causing the mosquito to become stuck on the adhesive plastic surface.