The falling numbers of insects is a big danger. Half of all insects have died since the 1970s. Over 40 per cent of insect species could die in our lifetime. They are dying at a rate of 2.5 per cent a year. It is an "insect apocalypse". Scientists say there could be, "a catastrophic collapse of Earth's ecosystems".

Pesticides are killing insects. Fewer insects mean less food. Our crops depend on insects. Around 7.5 billion people will have no food without insects. A big worry is honeybees. The number of honeybee groups dropped a lot. A professor said: "We can't wait another 25 years before we do anything because it will be too late."