Moles are most active in spring and fall, when moist soil makes digging easy and food sources like earthworms and grubs are plentiful near the surface. They don’t hibernate, so mole activity continues year-round, just deeper underground during summer heat and winter cold.
If your yard is suddenly covered in raised ridges and unsightly mounds, there’s a good chance a mole moved in while the soil conditions were just right.
Understanding Moles: What You’re Dealing With
The eastern mole (Scalopus aquaticus) is the species most homeowners in Colorado and across the U.S. encounter.
These are solitary animals built entirely for life underground. No external ears, paddle-shaped front feet, and a body weight of roughly 2.5 to 5 oz, yet they can tear through a yard fast. A single mole can dig up to 15 feet of new tunnels per hour when conditions are favorable.
They feed almost exclusively on earthworms, soil insects, and grubs. The more grubs in your soil, the harder it is to discourage moles from sticking around.
Here’s what makes them especially frustrating:
- They don’t eat plant roots directly, but their underground tunnels disturb root systems, dry out the soil around them, and cause grass to die off in strips.
- Moles tend to work just beneath the soil surface, leaving raised ridges that make mowing miserable and turn a clean lawn into a lumpy mess.
- They’re territorial but will expand their network when the food supply warrants it.
When Are Moles Most Active?
Moles are active year-round, but their behavior shifts with the seasons. Here’s a quick look at the pattern:
| Season | Mole Behavior |
| Early Spring | High surface activity, soil thaws and worms rise, tunnels multiply |
| Summer | Moles retreat to deep tunnels where soil stays cool and moist |
| Fall | Second peak, cooler temperatures bring worms back up, new tunnels appear |
| Winter | Deep activity continues, slows in colder climates, milder winters = active runways all season |
Early morning and late evening hours are when moles are most active during their peak seasons. That’s when surface tunnels get extended, and fresh soil pushes up.
Soil moisture plays a huge role. Moles feed where earthworms concentrate, and earthworms concentrate in moist soil.
The USDA’s Natural Resources Conservation Service notes that earthworms are a primary soil health marker and thrive in moist, well-structured soil, which is exactly what makes irrigated lawns disproportionately attractive to moles.
Effective Methods to Get Rid of Moles
Mole Traps: The Most Reliable Method
Trapping remains the most reliable method for removing moles. The two types that work best are:
- Scissor-jaw traps, placed directly over an active mole tunnel
- Pincher traps, inserted into the tunnel from the surface
Always wear gloves when handling mole traps. Moles have a strong sense of smell and will avoid tunnels with human scent. Set traps in pairs on either side of the active section. Check them every 12 to 24 hours.
For anyone in Colorado dealing with persistent mole activity before a lawn renovation, handling grub populations first makes trapping far more effective.
It’s also worth understanding how professional landscape maintenance keeps your soil healthy year-round, since consistently maintained turf recovers faster, even when minor tunneling does occur.
Castor Oil Repellents
Castor oil-based repellents are the most widely used non-lethal option. They work by making the earthworms and grubs in the affected area taste unpleasant to moles.
Granular castor oil-based deterrents are worked into the soil and watered in. Liquid castor oil repellents can be applied with a hose-end sprayer.
They won’t eliminate a mole problem permanently, but they can drive moles toward the edges of your property long enough to break their established tunneling patterns.
A few things to know before you apply:
- Reapply after heavy rain, since water dilutes the concentration
- Cover the entire affected area, not just the visible tunnels
- Castor oil works better as a deterrent than a removal tool
Grub Control: Removing the Food Source
If you can reduce the grub populations in your lawn, moles lose their reason to stay.
Colorado State University Extension’s guide on white grubs explains that grub control products work best when applied at the time of egg hatching in early summer, before larvae establish deep in the root zone.
Getting the timing right in the Centennial, Lone Tree, and Aurora areas can significantly reduce mole pressure by fall.
Wire Mesh and Physical Barriers
Lining garden beds or high-value planting areas with wire mesh about 12 inches below the soil surface can prevent moles from tunneling into those spots. It won’t stop them from working the rest of your yard, but it protects areas where plant roots matter most.
What Doesn’t Work as Well
Ultrasonic devices and vibrating stakes are heavily marketed as mole repellents. The evidence behind them is thin. Moles adapt quickly to consistent vibration in their environment, and multiple field studies have found them largely ineffective after the first few days.
How to Prevent Moles From Coming Back
Removing a mole is one thing. Keeping the next one out is harder, especially in yards with abundant food sources in the soil.
- Reduce irrigation slightly in areas not requiring it, since moist soil invites earthworm concentrations
- Keep up with grub prevention on a seasonal schedule
- Aerate and maintain healthy turf so root systems stay dense and resilient even if minor tunneling occurs
- Inspect the yard each spring when soil thaws and watch for new tunnels early before an extensive network develops
Frequently Asked Questions
How many moles are typically in one yard?
Most of the time, just one. Moles are solitary animals and actively defend their tunnel networks against other moles. If you’re seeing widespread damage across your yard, it’s likely a single mole with a very busy schedule rather than a colony.
Does castor oil actually work to repel moles?
Castor oil repellents can work, but they’re more effective at deterring moles from a treated area than eliminating an existing problem. They’re best used after trapping to prevent new moles from moving into a treated zone.
Are moles dangerous to humans or pets?
No. Moles have no interest in interacting with people or animals. The damage they cause is entirely to the lawn and garden, not to anything living above ground.
Can I use poison bait to get rid of moles?
Some products contain the active ingredient bromethalin and are formulated to mimic earthworms. These can be effective, but they require careful placement in active tunnels and carry risks if pets or other wildlife access them. Trapping is generally considered safer and more targeted.
There’s a Reason Professionals Exist
You could spend several weekends collapsing tunnels, resetting traps, and reapplying castor oil. That’s a legitimate approach.
But if you’re dealing with a recurring mole problem that tracks back to general lawn health, soil conditions, or grub populations you can’t seem to get ahead of, it starts to look a lot like a symptom of something bigger.
The team at Easy Green Landscaping works with lawns throughout Centennial, Aurora, Castle Rock, and surrounding Colorado communities, handling everything from seasonal maintenance to soil and turf care that makes yards less hospitable to burrowing animals in the first place.
Call us at (303) 766-3304 or message us here, and we’ll take it from there.
