Locusts by the millions are chomping their way across a large part of Africa in the worst outbreak some places have seen in 70 years.

The locusts are threatening some of the world’s most vulnerable countries, where millions of people already live with the periodic risk of drought or flooding.

“A typical desert locust swarm can contain up to 150 million locusts per square kilometre,” East African regional body the Intergovernmental Authority on Development (IGAD) has said.

Kenya Africa Locust Outbreak
A farmer’s daughter waves her shawl in the air to try to chase away swarms of desert locusts from her crops in Katitika village, Kitui county, Kenya (Ben Curtis/AP)
Kenya Africa Locust Outbreak
Desert locusts have swarmed into Kenya by the hundreds of millions from Somalia and Ethiopia (Ben Curtis/AP)
Kenya Africa Locust Outbreak
Farmers try to chase away the locusts from a tree on their land by shaking branches, banging sticks together and shouting (Ben Curtis/AP)
Kenya Africa Locust Outbreak
The insects are roughly the length of a finger (Ben Curtis/AP)
Kenya Africa Locust Outbreak
They are destroying farmland and threatening an already vulnerable region (Ben Curtis/AP)
Kenya Africa Locust Outbreak
Kenya has not seen a locust outbreak like this in 70 years, the UN’s Rosanne Marchesich said (Ben Curtis/AP)
Kenya Africa Locust Outbreak
It is also ‘the worst that we’ve seen in Ethiopia and in Somalia in 25 years’, she added (Ben Curtis/AP)
Kenya Africa Locust Outbreak
The further increase in locust swarms could last until June as favourable breeding conditions continue, the IGAD has said (Ben Curtis/AP)
Kenya Africa Locust Outbreak
Major locust outbreaks can be devastating (Ben Curtis/AP)
Kenya Africa Locust Outbreak
One between 2003 and 2005 cost more than 500 million dollars to control across 20 countries in northern Africa, the UN Food and Agriculture Organisation said (Ben Curtis/AP)
Kenya Africa Locust Outbreak
It caused more than 2.5 billion dollars in harvest losses (Ben Curtis/AP)
Kenya Africa Locust Outbreak
To help prevent and control outbreaks, authorities analyse satellite images, stockpile pesticides and conduct aerial spraying (Ben Curtis/AP)
Kenya Africa Locust Outbreak
In Ethiopia, officials said they have deployed four small planes to help fight the invasion (Ben Curtis/AP)
Kenya Africa Locust Outbreak
The UN has allocated 10 million dollars for aerial spraying (Ben Curtis/AP)
Kenya Africa Locust Outbreak
Humanitarian chief Mark Lowcock said families across the region ‘now face the prospect of watching as their crops are destroyed before their eyes’ (Ben Curtis/AP)