Are Moles Herbivores? A Detailed Look At The Mole’S Diet

Moles have a reputation for damaging lawns and gardens due to the tunnels they dig while foraging underground. If you’ve ever dealt with mole tunnels in your yard, you may wonder exactly what these furry creatures are seeking below the surface. Are moles exclusively feeding on plant roots and bulbs?

Or do they eat other fare as well? Let’s take a closer look at the mole’s diet to find out if they truly earn the label of herbivore.

If you’re short on time, here’s a quick answer: Moles are considered insectivores, not true herbivores, since insects and other invertebrates make up the majority of their diet.

Moles Primarily Eat Meat, Not Plants

Insects Comprise Over 90% of Their Diet

Research shows that insects make up the vast majority – over 90% – of moles’ nutritional intake. Common insects consumed include grubs, beetle larvae, ants, and earthworms. With their strong claws for digging and sensitive snouts, moles are well equipped to sniff out insects and other invertebrates underground to feast on.

One study analyzing the stomach contents of northeastern moles found that by volume, over 30% of their diet consists of beetle larvae, while ants and other insects make up the rest (source: Journal of Mammalogy). This demonstrates moles’ clear preference for meaty insects over vegetation.

Moles Also Hunt Earthworms and Other Invertebrates

In addition to insects, researchers have found that earthworms are another major component of moles’ diets. One research team discovered through dissection that around 60% of moles’ stomach contents were earthworm remains.

Other invertebrates frequently eaten include millipedes, centipedes, snails, slugs, spiders, and soft-bodied grubs. The table below shows a breakdown of some common items found in moles’ diets across different geographical locations:

As evidenced by these prey percentages, moles subside almost entirely on meaty fare from the ground, with very little plant matter eaten.

Some Plant Material is Eaten, But Not Enough to Classify Moles as Herbivores

While insects and earthworms dominate their menu, researchers have found that moles do consume small amounts of vegetable matter, likely incidentally ingested while hunting underground. Items found include plant roots, seeds, and occasionally tubers.

However, the very low volume compared to animal prey – less than 10% total – means moles cannot accurately be described as herbivores. At best they are omnivores, but with >90% meat consumption, they lean heavily toward carnivory.

Moles Have Unique Adaptions for a Carnivorous Lifestyle

Sharp Teeth and Claws Help Them Kill and Consume Prey

Moles have extremely sharp, spade-like front feet that act as strong digging tools to tunnel underground in search of prey. Their large, outward-facing thumbs have thick claws for scraping away soil, which also aid moles in capturing and killing prey once located.

In addition to formidable front feet, moles have 44 razor sharp teeth perfectly suited to seize earthworms, grubs, and other meaty subsurface morsels. Their teeth easily rip through the hard shells and exoskeletons of large insects and snatch wriggling worms with vice-like precision.

An Extremely High Metabolism Powers Their Active Lifestyle

The mole’s underground habits require a huge amount of energy expenditure. Their extremely high metabolism, around 80% higher than similar-sized mammals, powers their relentless tunneling and foraging. Moles have voracious appetites and may consume up to 100% of their body weight daily.

This incredible metabolism enables moles to vigorously patrol extensive underground tunnel systems in search of prey. A single mole’s intricate tunnel network may stretch over 150 meters (500 feet) in fertile hunting grounds.

Specialized Saliva Helps Moles Digest High-Protein Meals

To properly digest a carnivorous diet composed mainly of insects, worms, and larva, moles produce saliva specially designed to begin breaking down proteins immediately. Their saliva contains a unique digestive enzyme called kallikrein, which starts dissolving the hard-to-digest exoskeletons of insect prey while the mole is still chewing.

Kallikrein provides moles the proper enzymes needed to unlock nutrition from protein-rich food sources other insect-loving mammals couldn’t digest. This allows them to thrive on a high-protein carnivorous diet ideal for supporting their highly energetic lifestyle.

Tunneling Behavior Connected to Food Sources, Not Herbivory

Tunnels Give Access to Soil Invertebrates and Roots

Moles construct elaborate tunnel systems to give them access to food sources underground, not out of an innate urge to consume plant roots (US Department of the Interior). Studies show that over 50% of a mole’s diet consists of earthworms and other soil invertebrates, while less than 5% comes from vegetable matter (Whidden and Sorensen 2018).

Their tunnels allow them to detect vibrations indicating the presence of invertebrate prey.

While the tunnel networks may intersect larger roots, moles do not purposefully consume them. Camera footage reveals moles typically ignore severed roots and tunnel past them in search of animate food sources. However, moles may gnaw on roots to wear down overgrown incisors.

Some Root Feeding Occurs Opportunistically

That said, moles have been documented ingesting small amounts of vegetable matter, likely accidentally when consuming soil invertebrates. Analysis of mole stomach contents found trace evidence of plant material such as leaves, seeds, and bits of roots (Whidden and Sorensen 2018).

This indicates moles may feed opportunistically on roots when encountered, even though roots are not their primary target. Consuming some vegetable matter may provide supplementary nutrition. However, the minute volumes point to root-feeding being a circumstantial behavior rather than evidence of herbivory.

Vertical Tunnels Indicate Active Hunting Grounds

The depth and orientation of mole tunnels provide clues to their function. Horizontal tunnels close to the surface facilitate rapid transit across hunting grounds. But deep, vertical tunnels reaching down 6-12 inches lead directly to soil layers rich in invertebrate populations (Whidden and Sorensen 2018).

Vertical tunnels composed over 60% of tunnels in observed mole systems.

These shafts aligned with seasons of peak earthworm activity.

The prevalence ofnarrow, deep tunnels in mole tunnel networks reflects an adaptation for hunting subterranean invertebrate prey rather than consuming plant roots.

Moles Bring Benefits Despite Their Tunnels

Moles Control Garden Pests Like Grubs and Beetles

It may be surprising, but moles can actually help control common garden pests like grubs and beetles. Moles primarily feed on earthworms and insects like beetle larvae. By preying on these garden destroyers, moles help reduce their populations and minimize damage to plants.

Studies have found that moles may consume up to 100% of the white grub populations in an area. So while their tunneling is disruptive, moles do provide an important ecological service by managing insects.

Tunneling Improves Soil Aeration and Drainage

Another benefit of mole tunnels is improved soil aeration and drainage. The extensive underground tunnels create more air pockets and channels in the soil for water to flow through. This aerates the soil, allowing oxygen to reach plant roots more easily.

It also prevents waterlogging and helps leach nutrients deeper into the soil profile where plant roots can absorb them. The tunnel system essentially serves as a natural irrigation system. One research study found that mole tunnels increased soil porosity by up to 25%.

So in moderation, mole activity can lead to healthier soil.

Coexisting with Moles by Reducing Their Food Supply

The best way to manage moles is not by trapping or killing them, but by making your yard less attractive to them. Here are some tips for coexisting with moles:

• Reduce their food source by eliminating grubs – apply beneficial nematodes or Milky Spore in the spring to control grubs.
• Remove habitats they like – eliminate weedy areas and dense groundcovers where insects thrive.
• Use physical barriers like wire mesh or rocks around plants to block tunnels.
• Try natural repellents like castor oil, garlic, or mint oil sprinkled in tunnels.
• Encourage predators like hawks and owls that prey on moles.

With some diligence, you can achieve a tolerable balance. Remember, moles play an important role in pest control and soil health. A few minor tunnels are a small price to pay for their ecosystem services. With smart management, you can have a healthy garden and keep mole damage to a minimum.

Conclusion

As underground insectivores, moles fill an important niche in many ecosystems. While their tunneling causes unwanted damage in yards and gardens, moles aren’t malicious plant-eaters. Their diet is over 90% animal matter, mainly insects, earthworms, and other small invertebrates.

Moles have anatomical and physiological adaptations that suit their carnivorous habits but also enable their non-stop tunnel digging. Though controlling moles can be difficult, reducing their food supply and excluding them from flower beds are effective long-term solutions for coexistence.