Cockroaches can be dangerous to humans primarily as carriers of diseases, allergens, and triggers for asthma. They can spread a variety of harmful bacteria and viruses, including those causing typhoid, cholera, dysentery, salmonella, and other illnesses through contamination of food and surfaces. Additionally, cockroach droppings, saliva, and body parts can trigger allergic reactions and worsen asthma symptoms, especially in children. While cockroaches rarely bite humans, in extreme infestations they may gnaw on skin, causing irritation and potential infections. They also cause indirect harm by contaminating food and triggering allergic responses. Cockroach infestations often indicate larger unseen populations due to their rapid reproduction. In summary, cockroaches pose health risks through disease spread, allergic reactions, and asthma exacerbation, making them harmful pests that should be controlled promptly.