When the mosquito bites why does she inject an anticoagulant?

When a female mosquito bites, she injects an anticoagulant to prevent the host's blood from clotting. This allows her to feed more efficiently by ensuring a continuous flow of blood. The anticoagulant also helps her obtain the necessary nutrients for egg development. Without this mechanism, the blood would clot quickly, making feeding difficult and reducing her chances of reproductive success.