Two chemicals contained in baits for lawn moles are warfarin, 3-(alpha-acetonylbenzyl-4-hydroxycoumarin) and bromethalin. Warfarin usually comes in a form of gel, and bromethalin is usually contained in baits that are shaped as worms. These chemicals can damage the skin.
Warfarin acts by reducing the ability of the animal's blood to clot, causing the animal to die from internal bleeding once it eats the bait. Bromethalin reduces the level of oxidative phosporylation in the animal's body, leading to lower levels of ATP production and reducing osmosis. As a result, animal cells swell with water, the nervous system fails, and the animal dies.
To place the bait correctly, find the openings in the ground that lead to the lawn moles' tunnels. The openings are usually located next to trees, bushes and other places where a mole can hide. Put some dirt or debris at the exits, leave it overnight, and check for signs that a mole has touched those piles the next morning.
Place bait near the opening of active tunnels or directly inside the tunnels, making sure that pets or other animals don't accidentally get harmed by mole baits. Check the bait frequently, and add new bait if the old bait is gone or if new active tunnels appear.