Which insect is known for having a painful bite while feeding on blood?

The horse and deer fly are well-known for their painful bites, particularly when they feed on the blood of mammals. These flies possess sharp mouthparts that can cut through skin, allowing them to access blood. Their bites are often described as quite painful, which serves to deter potential threats and restricts movement from the host, allowing the fly to feed more effectively.

In contrast, the other listed insects do not have a reputation for inflicting significant pain through their feeding habits. No-see-ums, for example, do bite and can cause irritation, but their bites are not typically described as painful compared to those of horse and deer flies. Boxelder bugs and cinched bugs do not feed on blood at all; instead, they primarily consume plant material, making them irrelevant to the context of painful blood-feeding insects.