Billions of locusts (蝗虫) are moving through farms and fields in the East African countries of Ethiopia, Kenya and Somalia.
Locusts are grasshoppers. Normally grasshoppers don't travel in groups and so they do little harm. But when there are lots of them, their bodies and behavior change. That's when they become locusts. Locusts travel in huge groups, laying eggs along the way, which produce even more locusts. In a single day, a small swarm (群) of the insects can eat as much food as 35,000 people do.
The locust swarms in Ethiopia and Somalia are the worst in 25 years. These locusts are desert locusts. They began swarming about six months ago. By moving with the winds, desert locusts can travel up to 90 miles a day or more.
Locust swarms are more common when heavy rains follow a long dry period. The insects lay their eggs in the wet ground. This season, East Africa has had its heaviest rainy season in 40 years.
When the insects swarm, one square kilometer of land can hold as many as 150 million locusts. There are 700 square kilometers of land covered by the insects in Kenya alone.
The insects are a threat to lives in the region, where food is already in short supply. Already many farmers who keep animals are struggling because locusts have eaten out the plants the animals usually live on.
In East Africa, farmers have been shooting into the air or making noises in the fields, but that doesn't work against so many insects. Experts say that spraying pesticides (杀虫剂) over large areas from airplanes is the only way to reduce the number of insects. The UN has released (释放) $10million to help deal with the locust problem. The UN says about $70 million is needed to truly control the locusts with pesticides.
