Deroceras reticulatum is native to Europe, North Africa and the Atlantic Islands.

[2][3] It occurs widely in Europe, but is more rare and restricted to cultivated fields in the southeast, particularly in the Balkans, and is probably absent from Greece and the Bulgarian mountains.

[2] In the north and central European lowlands, Great Britain, and Ireland, it is probably the most widely occurring slug.

[2] Reproductive system: Penis is fleshy and with a silky sheen, in the shape of an irregular sac, in fully mature specimens divided into 2 parts by a deep lateral constriction.

[2] Vas deferens opens into penis wall facing the external body side.

[11] Deroceras reticulatum is almost exclusively restricted to cultivated areas, usually in open habitats, in meadows, near roadsides, in ruins, gardens and parks, not inside forests.

[2] Various carabid beetles are predators of Deroceras reticlatum, including: The bacterium Moraxella osloensis is a mutualistic symbiont of the slug-parasitic nematode Phasmarhabditis hermaphrodita.