WAMBA, Kenya — When the dense, dark smudge started blocking out the daytime sky, many in a sleepy pastoralist hamlet in northern Kenya imagined it was a cloud ushering in some welcome, cooling rain.

But the hope soon turned to terror when the giant blot revealed itself as a swarm of fast-moving desert locusts, which have been cutting a path of devastation through Kenya since late December.

The sheer size of the swarm stunned the villagers.

“It was like an umbrella had covered the sky,” said Joseph Katone Leparole, who has lived in the hamlet, Wamba, for most of his 68 years.

When the insects descended, the community quickly gathered to try to scare them off, using one arm to beat them with sticks or bang on metal pots, and the other to cover their faces and eyes as the bright, yellow insects teemed around them.