Feeding habit, vector activity, including dispersion, and host activity or whereabouts of the host are defining the limitations of a possible contact and thus relevant for vector-borne diseases.
According to dispersion, mosquitoes usually travel a few hundred meters from their emergence sites. Generally it is assumed that they do not fly further than 2 km, but have been recorded to be dispersed 100 km or more, usually assisted by the wind. Artificial dispersion via railway and aircraft also exists.
Apart from horizontal dispersion a definite vertical stratification in biting activity has especially been observed in many tropical forest mosquitoes. Some species bite mainly at ground level, while others are most active in the intermediate levels or in the forest canopy.