Why do black horse flys bite?

It's not entirely accurate to say black horseflies "bite". They actually pierce the skin with their sharp, saw-like mouthparts to draw blood.

Here's why they do this:

* Food source: Female horseflies need blood to produce eggs. They use their sharp mouthparts to cut through skin and access the blood vessels.

* Specific requirements: Unlike mosquitoes, which feed on nectar as well, female horseflies rely solely on blood for their protein needs.

It's important to note that male horseflies do not bite. They feed on nectar and pollen, just like many other insects.

So, while it feels like a bite, it's actually a blood-sucking process that female horseflies need for their reproductive cycle.