Bicoloured shrew

The Bicoloured shrew (Crocidura leucodon) is a small mammal belonging to the order Eulipotyphla and the family Soricidae. While it is naturally a beneficial insectivore, it is often considered a minor pest in agronomy due to its burrowing habits which interfere with the root development of cultivated crops.

The primary damage caused by these shrews is indirect. As they forage for insects, larvae, and earthworms, they excavate numerous tunnels within the topsoil. This activity disrupts the soil structure, leading to root air-exposure and dehydration in young seedlings, which can significantly weaken or even kill sensitive plants in vegetable gardens and cereal fields.

The biology of the species is defined by an extremely fast metabolic rate, requiring constant feeding. Shrews remain active year-round and do not hibernate, which means their burrowing activity continues regardless of the season. Their rapid reproductive cycle allows populations to establish quickly in agricultural areas where food sources are abundant.

Signs of infestation include surface tunnels and small soil disturbances. Unlike true rodents that feed directly on seeds or stems, the shrew's impact is focused on the root zone. Their tunnels often serve as highways for other pests, such as mice or voles, which may then cause further direct damage to the crop roots or tubers.

Effective management strategies focus on habitat disruption rather than eradication. Regular cultivation and deep harrowing of the soil are the most successful methods for collapsing tunnel networks and encouraging the shrews to move to adjacent non-crop areas. Using physical barriers or ultrasonic pest repellers can also help protect high-value plots from their activity.