Which two species of mosquitoes commonly enter houses at night?

The correct answer identifies Culex pipiens and Culex tarsalis as the two species of mosquitoes that commonly enter houses at night. Culex pipiens, often referred to as the common house mosquito, is well-known for its indoor activity during the evening and nighttime, making it a frequent nuisance in urban and suburban settings. Similarly, Culex tarsalis also exhibits nocturnal behavior and is more active during the night, often entering homes where it can find human hosts.

These species thrive in environments where they can easily access sheltered areas, such as homes, which offer warmth and potential food sources. Their preference for nighttime activity aligns with the behavior of many mosquitoes, which tend to feed during the dusk and dawn hours when it is cooler and more humid.

In comparing with other species such as Anopheles quadrimaculatus and Aedes aegypti, while they are also significant in various contexts, they do not share the same patterns of entering residences at night as Culex pipiens and Culex tarsalis do. This makes Culex pipiens and Culex tarsalis the notable choices for this question regarding their common nocturnal habits and tendencies to enter homes.