Slugs need a humid environment in order to survive, reproduce and move around. 90% of the slug population can almost always be found in the soil. Only 10% of the population comes out at night to feed on plant material. Most slugs are hermaphroditic, so both male and female.

Females lay their eggs in groups of 15 to 50 in the soil or under plant waste. Under favourable conditions these eggs hatch immediately. Under unfavourable conditions they can survive for a long period until circumstances improve, in order to hatch only then. Normally, there are 2 generations of slugs per year. However, in a wet summer there can be more generations.

Depending on the species, adult slugs are 30 to 150 mm long.

Slugs can devour the equivalent of half their body weight within 24 hours. The damage they cause can occur both aboveground and underground.

• In very young crops, they hollow seeds, strip leaves and eat roots and emerging cotyledons.
• In older crops, damage to flowers, tubers and roots lead to a serious reduction of quality.
• Feeding damage permits the entry of many kinds of plant diseases.
• Muscous secretion, especially in flowers and salad crops also results in loss of quality.