Amdro Ant Killer Bait. Can be used year round for consistent control of ants. Easy-to-use, dual-action formula works outdoors or inside to kill a variety of ant species. That means you can kill both sweet-eating and grease-eating ants with one easy to use product. Contain a bait formula that attracts foraging ants seeking food for their colony. They take the bait back home to share. Once the queen and other ants eat it, the colony is destroyed. Some ants die in hours. Larger colonies may take a week or longer.