The female which has not eaten yet, sets out at night in search of a host to bite. The location of the latter takes place at several levels. The identification of the attraction factors and the mechanisms for the location and reconnaissance of the host to be bitten are currently extremely important fields of research: at long distance, it is the olfactory stimuli which come into play, such as specific kairomones in animal (or human) species; at medium distances, other powers of attraction, such as the carbon dioxide emitted during respiration, come into play; at short distances, the heat of the host, his body humidity and various visual factors may play an important role. For the bite itself, the relative heat of the host is a fundamental factor. The species Anopheles gambiae is especially attracted by the smell of human feet, even at a distance, and will bite feet and ankles in preference. The action of the bacterial micro-fauna of the skin has recently been shown in these emanations. Unlike other mosquitoes, Anopheles gambiae is not attracted by smell from respiration.

The Anopheles mosquito often bites at night. In Africa, when a subject is bitten during the day, it is almost certainly not an anopheline. It is possible to be bitten by an infected Anopheles mosquito from dusk until dawn included. This risk is at its greatest in the middle and during the second part of the night: in fact, parous mosquitoes (i.e. those mosquitoes which have already laid eggs at least once and which are the only ones capable of infecting) are ordinarily occupied in searching for a place to lay eggs and the egg-laying during the first part of the night. Classically, the bite of an Anopheles mosquito is carried out in a single action; it normally lasts two or three minutes, and enables the female mosquito to completely refill its stomach. Most of the time, it is carried out on a sleeping subject. It is here that it differs from the bite of other species of mosquitoes, such as the Aedes, which bite during the day and bite the same person a number of times or different persons before having had a complete blood meal. 

During the bite, the blood is sucked by a pumping action after the direct piercing of a blood vessel. Less frequently, it may be sucked from a micro-hemorrhage following the penetration of the injurious mouth parts. The saliva is ejected throughout the duration of the bite, from the beginning of the penetration of the mouth parts until the stomach is completely full. The saliva contains anticoagulants, inflammatory substances, digestive enzymes and vasodilators.

By definition, the tendency to bite Man is known as anthropophilia, the tendency to bite animals zoophilia.

Once the blood meal is finished, the digestion starts. Digestion of a whole meal normally takes around forty hours. The blood is firstly concentrated by eliminating the water: the abdomen, heavily distended, which appears red due to its transparency at the end of feeding, becomes dark brown and its volume decreases gradually as digestion progresses.

Simultaneously, the ovaries develop. The females who have already laid require only a blood meal to be able to perform egg-laying. The females yet to lay sometimes need two meals to complete the development of their ovaries: they are referred to as being in a pregravid state. 

Once the eggs are mature, the female sets out in search of a place likely to favor egg-laying. As for the search for a host to bite, olfactory stimuli are perceived at a distance by the female and enable her to locate them. At short distances, the physio-chemical characteristics of the water are analyzed. Egg-laying generally takes place after dusk. Once this is complete, a new cycle starts. 

For those females that have never laid, nulliparous females, the first blood meal comes two or three nights after emergence. For the females who have already laid, (i.e. who have laid at least once), taking a blood meal usually occurs a few hours after the eggs have been laid, the same night.  

The duration of the trophogonic cycle is well known for the vectors of tropical Africa: it varies between two and three days for females who have already laid, depending upon the species and the seasons. For the females yet to lay, it is longer, up to five days, due to the pregravid phase.