The diet of slugs includes living and dead plant material, fungi and earthworms. Almost always slugs are very voracious.
The Spanish slug is considered among the 100 worst alien species in Europe. It is believed that they spread mostly embedded in horticultural soils and potted plants distributed around Europe. Because slugs can multiply explosively under favorable conditions, they have become a major horticultural pest.
Since the 1990s, the Spanish slug has rapidly conquered more and more areas and has invaded nearly every garden in the Europe.