Garden snail  (Helix aspersa)

Calcareous: containing free calcium carbonate, chalky.
Hermaphrodites: possessing both male and female sex organs.
Hibernate: a winter survival strategy characteristic of some mammals in which an animal's metabolic rate slows down and a state of deep sleep is attained. Whilst hibernating, animals survive on stored reserves of fat that they have accumulated in summer. In insects, the correct term for hibernation is 'diapause', a temporary pause in development and growth. Any stage of the lifecycle (eggs, larvae, pupae or adults) may enter diapause, which is typically associated with winter.
Nocturnal: active at night.
Self-fertilise: fusion of male and female sex cells (gametes) from one individual. In contrast, in cross-fertilisation, two different individuals are involved.

1. National Biodiversity Network Species Dictionary (March 2003):
   http://www.nhm.ac.uk/nbn
   
2. Pfleger, V. & Chatfield, J. (1983) A guide to snails of Britain and Europe. The Hamlyn Publishing Group Ltd., London.
   
3. Kerney, M.P. & Cameron, R.A.D. (1979) A field guide to the land snails of Britain and north west Europe. William Collins Sons and Co. Ltd., London.
   
4. Brown garden snail: University of Florida Department of Entomology and Nematology. (March 2003):
   http://creatures.ifas.ufl.edu/misc/gastro/brown_garden_snail.htm
   
5. Janus, H. (1982) The illustrated guide to molluscs. Harold Starke Ltd., London.
   
6. Koene, J. M. & Chase, R. (1998) Changes in the reproductive system of the snail Helix aspersa caused by mucus from the love dart. The Journal of Experimental Biology, 201: 2313-2319.
   
7. Buczacki, S. (2002) Fauna Britannica. Hamlyn, London.