Three things — (1) gardeners, (2) snails, and (3) the question of whether the latter (not the former) have a homing instinct — dominate the narrative in this new study:
“Snails home,” David J. Dunstan [pictured here] and David J. Hodgson, Physica Scripta, vol. 89, no. 6, 2014, 068002. The authors, at Queen Mary University of London and the University of Exeter, Penryn Campus, Penryn, Cornwall UK, report:
“It has frequently been reported that snails that are marked and removed from a garden are later found in the garden again…. We report a systematic study of the snail population in a small suburban garden, in which large numbers of snails were marked and removed over a period of about 6 months. [We] infer the existence of two groups of snails in the garden: members of a larger population that show little affinity to the garden itself, and core members of a local garden population that regularly return to their home if removed. The data are strongly suggestive of a homing instinct, but also reveal that snail-throwing can work as a pest management strategy.”
Here’s detail from the study:
Karen Kaplan reports further details in the Los Angeles Times, under the headline “Snails in your garden? Warm up your throwing arm, scientists suggest“.
BONUS: A set of now-old-fashioned guidelines for dealing with snails and slugs in one’s garden
BONUS (possibly unrelated): “Sluggish Data Transport Is Faster Than ADSL“
UPDATE BONUS: “Slime: A new way to protect plants from slugs“