The insects have been allowed to get out of control because the government hasn't got enough money to fight them.
The locusts have now invaded about 450 hectares of land and many crops have been destroyed.
Locusts are normally shy, solitary creatures. But in a swarm they become a pest, capable of stripping fields of crops in a matter of hours.
Duck counter-attack
But Madagascar isn't the only country coming under attack.
Locusts are also swarming near Beijing in China, where experts are planning to release thousands of ducks in an attempt to gobble them all up.
And there have also been reports of a swarm on the India-Pakistan border.
But while the damage locusts can cause to crops is very bad, they have never been known to attack humans.
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