Trudy Taylor of Aquinnah has a “hole” lot going on. She called last Saturday morning with an inquiry about a houseplant harasser.
It seems that something is afoot among her flowers. Her houseplants are being disturbed by a dastardly digger! Someone or something has been excavating the soil in her potted plants. The culprit digs a hole and removes the soil, leaving it in a pile next to the pots.
Which wild thing is blame can be answered if you burrow deeper into the details.
On the outside, in all of our yards, there are a variety of perpetrators that plow our plants and nose around the neighborhood. Look closely and make observations before placing blame.
Raised linear soil tunnels the size of a fist that have no visible entrance or exit areas could be the work of moles. But if you find a shallow burrow and there is no soil piled up near its inconspicuous entrance, you must note the size of the entrance hole before making any accusations. If the hole is about one inch wide, you might soon be face to face with a shrew. A slightly larger hole, at up to 1.5 inches across, could belong to a meadow vole. Meadow voles are also to blame for surface runways in grass, or tunnels beneath the snow.
Go up a size (to two inches) and that hole could have been made by squirrels. Do worry if you see a two-to-three inches hole with lots of digging and very loose granular soil, because that would likely mean you have rats! If you live near fresh water and the entrance hole is four inches wide, a muskrat might be your neighbor.
Deeper burrows with soil spread around the entrance tell a different story. Off the Island, consider that woodchucks have holes that are 10 to 12 inches [wide], while a badger is to blame if the entrance is one foot or more!
If you observe swirl-shaped digging, but no holes or burrows, you may have skunks, squirrels or raccoons rooting around your lawn for insects and/or nuts.
While this is all good information, Trudy is still looking for answers to her indoor potted plant incidents. I suggested that perhaps she has mice rooting around; they would do this type of damage. Trudy wondered if it were insects burrowing in the soil to overwinter. While a possibility, most insects would not leave the excavated soils outside of the pot, but would simple wiggle below it.
And of course the size of the hole argued against insects. Many insects do inject eggs into the soil to overwinter, but, like the cricket, use a long, needle-like ovipositor, so don’t need to do any excavation at all.
There are a few other insects that would leave a pile of soil after disrupting a plant. Some ground-nesting bees and wasps do this, although they generally prefer sandy soils to rich potting soils.
The insects that do cause problems to indoor plants include scale insects like mealy bugs and white flies, spider mites and aphids, but those pests do damage mainly to plant tissues, including leaves and stems, and generally won’t concern themselves with what’s under the surface.
My last offer of blame would be (perhaps surprisingly) to frogs, some of which do burrow underground for the winter and might have somehow gotten into Trudy’s house and into her plants.
Unfortunately, there are a lot of possibilities, and no certainties that I can offer her, without an all-night stakeout. I do promise that I will keep considering her dilemma and do a bit more research. I may just find the answer if I dig a little deeper.
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.