International Rock Flipping Day

Garlic Glass-snail | Oxychilus alliarius (left) and Vallonia sp. (right)

Today is International Rock Flipping Day and in celebration I went out into our garden and turned over a few bricks to see what I could find. Despite living in a fairly urban environment our garden has attracted a number of interesting insects, reptiles, amphibians, arthropods, gastropods, arachnids, and birds. We’ve found Clouded Salamander (Aneides ferreus) under rotting wood beside our crawlspace entrance, and a Common Gartersnake (Thamnophis sirtalis) took up temporary residence in one of our lesser used composters this summer. Wood bugs and pill bugs are legion.

Sow Bug
Sow Bug

Today I turned over a paver in our garden but the faster inhabitants were too quick to get good images of. Small centipedes wriggled and streaked their way to the edge of the brick and then back under into the darkness. Sow bugs were a little slower but not cooperative. Unfortunately, there were no pill bugs under this brick as they are fairly easy to photograph when they are rolled up.

It was only after all the more visible fast moving creatures had made their way to safety that I noticed the snails. There were several very small snails on the underside of the brick. After doing a little research I think that the blue snail is a Dark-bodied Glass-snail (Oxychilus draparnaudi), an introduced species, but I’d definitely welcome a positive id! The paler, translucent snail I think is a juvenile but again, I’d love a second opinion. See below for a revision on the identification.

Vallonian sp.
Vallonian sp.

Update: After consulting Land Snails of British Columbia (Robert G. Forsyth) I realized that the snail that I photographed was just too small (about 6mm) to be O. draparnaudi. Today (September 21) I went out to have a second look and to try the diagnostic test – if the snail smelled of garlic when “handled” it was likely a Garlic Glass-snail (O. alliarius). Sure enough – I relocated the snail, gave it a little nudge and a strong smell of garlic was the result! Robert had a look at the photographs and suggested that the paler snail is a Vallonia, possibly V. pulchella or V. excentrica.

Be sure to check out more of the fascinating finds turned up by other International Rock Flipping Day bloggers. This year’s event is being graciously hosted by Wanderin’ Weeta. For snail and slug enthusiasts (I know you’re out there!), visit Rob Forsyth’s excellent website at

Read on for a list of participants in this year’s International Rock Flipping Day:

And don’t forget to check the Flickr group, too.