How Do Exterminators Kill Moles?

Moles are notoriously difficult lawn pests to combat, which is why homeowners often resort to calling in professional exterminators. Most exterminators use traps to rid a yard of moles. Choosing the right type of traps and where to put them is key to the successful extermination of moles.

To understand how an exterminator eliminates moles, you have to know a little about the animal itself. Moles are insectivores, with diets comprised mostly of earthworms and grubs. These mammals spend their lives in underground tunnel systems. They are generally solitary, territorial creatures and spend most of their time burrowing through soil in search of food, according to Thomas G. Barnes, wildlife biologist for the University of Kentucky Cooperative Extension Service.

Moles can quickly compromise a yard by digging underground tunnel systems. They produce two types of tunnels, Barnes says: shallow and deep. Moles dig shallow tunnels to find easy-to-obtain food. The exposed dirt ridges that you see running through a mole-infested yard are evidence of these shallow tunnels.

Deep tunnels are more permanent creations that serve two purposes: connecting the tunnel systems and creating a more regular food source. According to Barnes, deep tunnels may also contain an expanded section where a nest is located. The dirt mounds that dot an infested yard are actually piles of surplus soil pushed to the surface when a mole digs out a deep tunnel. Moles rarely emerge from these mounds, but do so occasionally to collect vegetation for their nests.

Trapping is the most effective method for exterminating moles, reports the Ohio State University Extension, but traps are only successful when placed in active tunnels. Because shallow tunnels typically dead-end and not revisited by the mole, exterminators do not usually set traps in these tunnels.

Exterminators set up mole traps by creating a blockage of dirt in an active, deep tunnel before setting the trigger for the trap within that blockage. According to Barnes, the idea is that the mole will come barreling down the tunnel and try to remove the blockage, thus triggering the trap, and its sudden death.

Scissor-jaw, harpoon and choker-loop traps are three main types of traps for mole extermination. These traps are designed to kill a mole by either clamping down on it (scissor-jaw trap), impaling it (harpoon trap), or strangling it (choke-loop trap). Most professional exterminators use scissor-jaw traps to rid an area of moles, reports the Tulsa Master Gardeners website.

Other methods for mole extermination exist, but professional exterminators tend not use them. Grub-control chemicals, sonic repellers, tunnel flooding, and toxic mole bait are all common recommendations for homeowners with mole problems, says the Washington State University Integrated Pest Management program's website. Yet, unbeknown to the novices who try these methods, the biology and lifestyle of the mole render most of these solutions ineffective.