by Andrea Laine, EMGV

A mole has taken up residence in my yard and, seemingly overnight, disrupted a couple of landscaped ornamental beds and killed two biennials. Well, it’s time to send that critter an eviction notice!

I immediately installed a spike as I’ve experienced good results with them in the past. These low-tech devices periodically emit a sonic vibration that supposedly moles find irritating. It worked, somewhat; The critter vacated the one bed, waddled (I imagine) across the walkway leading to my front door and dove into the next nearest bed to begin again. Aargh.

So, I poked another spike into the soil thinking, “can’t hurt, might help.”  True enough–no moles were hurt. Extension resources say my go-to solution has not been scientifically proven effective.

Know thy enemy
Solving a problem is more difficult when you know next to nothing about its cause. It was time for me to do some reading and uncover a few facts about moles:

• Moles are solitary animals and, since they live underground, have few predators (snakes and foxes are two). Three to five moles per acre are considered a high population for most areas.
• Moles are carnivores; they prefer to eat insects and grubs. They eat 70% or more of their body weight each day. With an appetite like that it is no wonder they cover so much (under)ground.
• Moles are very efficient at tunneling. Observe their front feet in the accompanying photo and you can see why. The feet are broad and flat with long, protruding claws to help toss soil aside. They “swim” through the soil. They can tunnel forwards or backwards. Their deep (10 to 18 inches) and wide tunnels can destroy plant roots in their path, which is likely what happened to my biennials.
• Moles do not eat plants. If you notice plants or their roots suddenly vanishing, that is the work of white-footed mice or voles who are opportunistic herbivores – they make use of a mole tunnel to reach their food source.
• In addition to grubs and insects, moles eat earthworms, spiders and other beneficial soil microorganisms. Moles like shaded, moist, cool loamy soil. No one warned me that a reward for improving my clayey soil would be moles. They also enjoy mulched areas and compost piles.
• North Carolina is home to two species of mole: the Eastern mole and the star-nosed mole. The latter is a rare species and thus, moles are a protected species in this state.

Actions that may solve a mole problem
A 24-inch square piece of hardware cloth, bent in half and buried in the soil may work to protect a small area or a treasured plant. This option is hardly practical for my larger landscape and besides, I treasure all my plants.

Chemical repellents, toxicants and fumigants are not recommended as their effectiveness is limited at best and potentially dangerous to humans, pets and other wildlife. Extension also recommends not planting Euphorbia latharis (mole plant) nor Ricinus communis (castor bean plant) for similar reasons.

The most effective way to control moles is to trap them. Since moles are a protected species in N.C., you need a depredation permit to trap them. Depredation refers to wildlife causing property damage.

Benefits moles bring to nature
I am highly unlikely to experiment with trapping a mole, permit or not. And the problem would have to get pretty bad before I paid someone to trap a mole for me. So, it is time to consider what benefits moles bring to nature. Maybe we can coexist.

• For starters, moles eat white grubs and the larvae of pest insects. Grubs become Japanese beetles so hooray for moles.
• Tunneling loosens and aerates the soil. It also mixes the soil near the ground surface with deeper subsoil.
• Borders of marigolds may repel moles from gardens. This method has not been scientifically tested but who would object to planting marigolds? Thus, I am counting it as a benefit.

Alas, there are just too few benefits of moles in the landscape. Sigh.

Drawing a conclusion
I might have won the battle, after all. One source noted that spring floods are probably the greatest danger to adult moles and their young. I know it’s not spring, but Hurricane Flo just dropped several inches of rain on Durham. Maybe the two inches of water that seeped from the over-saturated soil into my basement was also enough to wash away the smorgasbord that my resident mole was enjoying and he will soon pack up for new digs. Wishful thinking? Can’t hurt, might help me feel better.

Further Reading:

Find lots more detail about moles and trapping them at this resource from Penn State Extension:  https://extension.psu.edu/moles

https://wayne.ces.ncsu.edu/2015/12/moles-or-voles/

https://extension2.missouri.edu/G9440

https://www.ncwildlife.org/Licensing/Regulations/Nongame-and-Other-Regulations/Wildlife-Depredation

http://www.metromastergardeners.org/faq/index.php?action=artikel&cat=9&id=20&artlang=en

Photo credits:
Mole: https://www.almanac.com/pest/moles
Marigold:  Sarbast.T.Hameed [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 4.0  (https://creativecommons.org/licenses/by-sa/4.0)], from Wikimedia Commons