As forests shrink and wildlife populations decline, mosquitoes may be increasingly turning to humans for their blood meals, according to a recent scientific study. Researchers warn that this shift could raise the risk of mosquito-borne diseases affecting people.

A new study published in the journal Frontiers examines how deforestation and habitat loss are changing mosquito behavior. As plants and animals disappear from forested areas, mosquitoes lose many of their traditional blood sources and are more likely to feed on nearby human populations.

How Deforestation Changes Mosquito Behavior

Deforestation reduces biodiversity by removing the animals and plants that mosquitoes have historically relied on for food. At the same time, human development often brings more people into these altered environments.

Researchers explain that when natural hosts leave or disappear, mosquitoes adapt. Rather than traveling long distances to find animals, they tend to feed on humans who are closer and more accessible.

Studies cited in the research show that heavily deforested areas often experience:

• Higher mosquito populations
• Greater contact between mosquitoes and humans
• Increased rates of mosquito-borne diseases

Disturbed environments tend to favor mosquito species that thrive near people, while the loss of biodiversity removes animals that can help “dilute” disease transmission.

Evidence from Brazil

The study highlights findings from parts of Brazil where forests have been significantly reduced. In areas that were once uninhabited forest, researchers detected human blood in multiple mosquito species.

These regions were previously part of large, intact forest ecosystems. Today, only a fraction of that forest remains due to deforestation and development, increasing human–mosquito contact.

Why Mosquitoes Bite Humans

Only female mosquitoes bite. They require blood to obtain the protein and iron needed to develop their eggs. While most mosquito species prefer animals, many will bite humans when other hosts are unavailable.

There are more than 3,500 mosquito species worldwide, but only a small number strongly prefer human blood. However, environmental changes can push even normally animal-feeding mosquitoes to bite people more frequently.

Public Health Implications

Mosquitoes are responsible for transmitting diseases such as dengue, Zika, yellow fever, chikungunya, and others. According to global health authorities, vector-borne diseases account for a significant share of infectious illnesses worldwide and cause hundreds of thousands of deaths each year.

Researchers emphasize that land-use decisions, environmental protection, and mosquito control all play important roles in reducing disease risk. How humans shape the landscape can directly influence mosquito behavior and the likelihood of disease transmission.