Street lights and other forms of artificial lighting could be causing a decline in insects. Researchers from the UK Centre for Ecology and Hydrology conducted studies on the number of insects living near sources of white light from LEDs. The researchers said LEDs are disrupting insect behaviour and causing a fall in their numbers. The lead researcher said the results of his study were "eye-opening". He was surprised at how much LEDs affected the number of insects. He found a 47 per cent reduction in insects near hedgerow test sites and a 37 per cent reduction near roadside grassy areas.

Researchers set up LEDs at 26 roadside sites in the countryside that contained hedges or grassy areas. They counted the numbers of moth caterpillars found at these sites and compared these with insects found at unlit sites. A researcher said: "We were really quite taken aback by just how stark [the difference] was." He suggested that LEDs caused two drastic changes in behaviour. He said the lights stopped female insects laying eggs in the lit areas. In addition, artificial lighting disturbed the feeding behaviour of the insects, so the caterpillars in the unlit areas were heavier.