The message
from TheOldFellow contains these words:

Interesting. The thought occurs to me that it might work in an acid
soil (like mine), but not in neutral or alkaline. An electrolyte
will certainly be necessary, water will probably do well, hence the
failure of tape on dry concrete.

The electrolyte would be provided by the slug...

Well, as I said, the experiment continues. No slugs so far, even under
a nearby slate laid for the purpose. They'll be here soon though...

Want some?

--
Rusty
Growing old is mandatory; growing up is optional.
Direct reply to: horrid dot squeak snailything zetnet point co period uk