Mole Problems Surface Early

It might be the weather. It might be growing intolerance. But here it is early April, and "mole rage" is already widespread throughout the state.

That means it's time to brush up on the mole facts. Not the faulty assumptions, mis- statements, erroneous conclusions and blatant lies that pass for information about this common landscape nuisance.

The worst offense committed in the name of mole control is the great landscape lie that insecticides will cure the problem. This mistake has been going on for a very, very long time and it seems to be constantly perpetuated by several things. One, many people want to believe there is a simple cure for complex problems. Two, there is a hint of logic to the gross oversimplification. Three, chemical control for moles is part of our folk-lore (as in, that's how we did it in the past). And finally, there is a great profit motive on the part of "pesticide peddlers" to sell insecticides and insecticide application services, even unnecessary insecticides that waste homeowner time and money and needlessly contribute to pesticide over-use.

The full story on moles is in ISU Extension Pamphlet Pm-1302b, "Managing Iowa Wildlife: Moles." Below are discussion points about moles. The handy checklist makes a convenient guide for answering questions about moles.

Mole Musings...

  • Moles are mostly solitary. (1 acre land = approx. 3 moles) (It only looks like there are hundreds!)
  • The "Main Mole Meal" is earthworms supplemented with some insect larvae, centipedes, millipedes, and spiders
  • Moles eat more than their own weight in earthworms daily (HIGH metabolism!)
  • Having moles doesn't necessarily mean you have grubs
  • Applying insecticides for grubs will not solve the mole problem
  • Eliminating earthworms is neither practical or prudent. White grub insecticides do not control earthworms (fortunately!)
  • Moles DO NOT eat bulbs, roots, pets, or small children
  • Moles are active year-round
  • Activity near the surface occurs in early morning and late afternoon in the spring and fall and on cloudy, damp days of summer.
  • The rest of the year is spent in deep tunnels 6 - 24 inches under the surface.
  • Surface runways may be used only once
  • Main runways may be used for years
  • Moles are woodland/woodland edge critters
  • Well-drained, loamy soils are their favorite haunts
  • Moles are built for digging: They can dig surface runs at 1 ft. per minute!
  • Moles hear well, though they have no external ears
  • Moles see poorly (light/dark) as the eyes are covered with fused eyelids
  • Benefits of moles:
    • soil mixing
    • soil aeration
    • water penetration to deeper plant roots
    • some biological control of destructive insects such as cutworms
  • Problems moles cause:
    • disfigurement of lawns, golf courses, cemeteries
    • dislodge bulbs, roots, expose them to air
    • rarely, consume small plant roots
  • Mole control options:
    1. Correctly identify the offending critter
    2. Locate active, main runs
    3. Decide if damage is worth the effort
    4. Purchase and set mole traps, being careful to follow label directions.
    5. If pit-fall trapping, relocate to a legal area at least several blocks away
    6. Inspect lawn for grubs. Don't assume they are present. Treat with insecticide ONLY if white grubs are present
    7. Maintain vigilance!
  • NON-Options (These "controls" do not work!)
    1. Sonic, ultra-sonic and electromagnetic devices.
    2. Repellents (early, encouraging results using castor oil repellent have not been consistent through further testing)
    3. Chewing gum
    4. Grain-based mole poisons
    5. Gassing is only occasionally effective

This article originally appeared in the April 3, 1998 issue, pp. 34-35.


Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on April 3, 1998. The information contained within may not be the most current and accurate depending on when it is accessed.