Which pest is known for causing health-related issues and is often identified by bites?

The correct choice is bed bugs, as they are well-known for causing health-related issues primarily through their bites. Bed bugs feed on human blood and their bites can result in various symptoms, including itchy welts, allergic reactions, and in some cases, secondary infections due to scratching. Beyond the physical discomfort, the presence of bed bugs can also lead to anxiety and insomnia, contributing to overall mental health concerns.

Fleas, while also impactful through bites, are more commonly associated with pets and can transmit diseases, but they are not as frequently found in indoor environments as bed bugs. Ants can cause nuisance issues, and although some species can bite, they don't typically lead to health-related problems in the same persistent manner as bed bugs. Termites, on the other hand, do not bite humans or cause health issues; they primarily damage wood structures, leading to significant property concerns rather than health hazards. This focus on bites and the resulting health impact makes bed bugs the most relevant answer in this context.