The female lays the eggs in shallow water. The hairy larvae live at the bottom of the water and are well camouflaged amongst the silt. They emerge after about 2-5 years, and usually under the cover of darkness.
They are often seen flying leisurely over mountain streams or a river; they also occasional show up at a pond. They are also typically seen flying over heath land. Their bright yellow and black stripes make them easy to identify, even from a fair distance away. They feed mainly on insects ranging from small prey such as midges to flies, butterflies and even bumble bees. This strikingly-coloured insect is incredibly aerobatic and they sometimes fly very high up into the sky.