Moles
Why have none of us seen a mole?
It is because moles spend almost all their lives underground in a system of permanent and semi-permanent tunnels, and when they do come out above ground it is usually at night.
Moles need a deep soil – we have no evidence yet of moles at Croft Close Nature Reserve but plenty at Long Meadow.
You can find moles by looking for mole hills. Here you can see some mole hills photographed in Long Meadow in March. They appear along a line. We know the mole has a tunnel following that line of mole hills. When a mole is digging a tunnel the earth has to go somewhere. The mole hill is a pile of loose earth shoved up from the tunnel below. They often have a system of permanent deep burrows, some used by several generations. This can be over 100m long.
Moles are specially adapted for their underground life. They have really outsize front paws. They have very poor vision and small ears and are thought to hear at low frequencies.
What about oxygen? The mole has adapted to use less oxygen than we do which makes life underground possible. They also develop air vents for their tunnel systems – we see the top of these as mole hills.
A mole can dig up to 20 metres of tunnel in a day using its spade-like forepaws to effectively breaststroke its way through the soil. If you want to see a mole on the move try this BBC video by Chris Packham. (Approximately 5 minutes).
What does a mole tunnel system look like? Very complex! Moles create tunnels at different depths and for different purposes.
They usually have:
nest chambers to sleep in or to house their new born offspring
a storage chamber for food and a deep chamber for waste
exit holes to the surface and ventilation and earth removal shafts (topped by a mole hill)
main passageways at different depths with connecting passageways.
Each mole lives in its own system of tunnels which is continually being extended.
The near surface tunnels are created in that part of the soil depth preferred by earthworms and other invertebrates like wood lice, earwigs, millipedes, and the grubs and pupae of insects like the cockchafer.
Earthworms are the most important component of the mole’s diet especially in winter; an 80g mole needs 50g of earthworms per day.