The European mole grows to around 15cm (6 inches) in length and must consume around two thirds of its bodyweight a day in worms and bugs to survive.
The mole digs a series of tunnels in which it can access it prey. As it digs its tunnels it compacts much of the waste soil against the tunnel walls to help ensure that the tunnel does not collapse. Any remaining soil is pushed upwards and out through a vertical vent. This is the soil which becomes a molehill on your lawn or field. The mole will then create further molehills as it excavates more tunnels and as it maintains those already in existance.
The damage above the ground is all-to-obvious but unseen damage below the ground also occurs as, although the mole does not eat plant roots, its tunneling activities will undermine plants and leave plant roots out of contact with the soil. Moles will also bite through roots which get in their way.
As well as causing unsightly blemishes on lawns, parks and gardens, moles also cause even greater problems on farmland including silage contamination, reduction in yield, damage to machinery, damage to geminating crops, weed invasion and damage to drainage systems and watercourses.
Moles may be small but they are highly aware of their little bit of the world. Their acute senses allow them to detect the slightest changes in temparature, humidity and air pressure within their tunnel network. Furthermore, they have a highly developed kinaesthetic sense (a memory-imprinted pattern of muscle impulses) which they use to find their way around the network of dark tunnels.