Metaldehydeis an organic compound. It is the cyclic tetramer of acetaldehyde. Metaldehyde is applied as a molluscicide bait for controlling slugs and snails in a very wide range of agricultural and horticultural crops. It is commonly used in wet coastal areas worldwide. It is toxic to all animals that ingest it. Metaldehyde is the only pesticide approved for use on all crops. A crop or vegetable garden is at its greatest risk of slug damage when plants are young. It is best to bait at planting time or at seeding.