Gadfly facts for kids

Gadfly is a common name for certain types of flies that really annoy animals, especially mammals like cows, horses, and even humans! These flies are known for their painful bites and for bothering animals so much that the animals become very restless and irritated.

What is a Gadfly?

The term "gadfly" isn't for one specific insect. Instead, it's a general name used for several kinds of flies that bite and bother animals. The most common flies called gadflies are horse-flies and botflies. They are a type of ectoparasite, which means they live on the outside of another animal and feed on it.

Horse-flies

Horse-flies are often large, sturdy flies with big eyes. They are found all over the world, especially in warm, humid places near water.

Appearance of Horse-flies

Horse-flies can be different sizes, from small to quite large, sometimes over an inch long! They often have shiny bodies and colorful eyes that can look green or gold.

Why Horse-flies Bite

Only female horse-flies bite. They need blood to get the nutrients required to produce their eggs. They use their sharp mouthparts to cut the skin of an animal and then lap up the blood. Their bites can be very painful and can even draw quite a bit of blood.

Where Horse-flies Live

You'll often find horse-flies near water, like ponds, lakes, and swamps, because that's where they lay their eggs. They also like wooded areas and pastures where animals graze.

Impact on Animals

When horse-flies bite livestock like cattle and horses, it can cause a lot of stress. Animals might run around wildly to try and escape the flies, which can make them tired and even lose weight because they're not grazing properly.

Botflies

Botflies are another type of fly sometimes called a gadfly. They are known for a very unique and sometimes strange life cycle.

Botfly Life Cycle

Unlike horse-flies, adult botflies usually don't bite. Instead, the female botfly lays her eggs on an animal's fur, skin, or even on other insects that will then carry the eggs to an animal. When the eggs hatch, the tiny larvae (also called "bots") burrow into the animal's skin or are swallowed.

Where Botfly Larvae Develop

The botfly larvae then live and grow inside the animal's body, often under the skin, in the stomach, or in nasal passages, depending on the type of botfly. They stay there for a period, feeding on the animal's tissues. Once they are fully grown, they leave the animal's body to fall to the ground and turn into adult flies.

Impact on Animals

While botflies don't bite as adults, the larvae living inside an animal can cause irritation, discomfort, and sometimes more serious health problems. Animals might scratch or rub themselves a lot to try and get rid of the larvae.

Why are they called "Gadflies"?

The word "gad" used to mean a sharp stick or a goad, which was used to poke or drive cattle. So, a "gadfly" is a fly that "goads" or pokes animals, making them restless and agitated, just like a stick would. This name perfectly describes how these flies bother animals.

How to Deal with Gadflies

For animals, farmers often use special sprays or treatments to protect their livestock from these annoying flies. For humans, wearing long sleeves and pants, and using insect repellent, can help prevent bites when you're in areas where these flies are common.