As Matt Levine writes on 22 October:

Apparently if you use a London office building for agricultural purposes, it is exempt from local property taxes. At first glance it seems hard to use a London office building for agriculture, but tax arbitrages bring out the best in human ingenuity, and one guy figured it out. If you get two snails and put them in a box in your office building, you are “breeding snails” and thus doing agriculture.

Matt Levine

Then of course there is an interview where someone talks to the guy doing the snail farming:

The farmer, a 79-year-old former shoe salesman called Terry Ball who has made and lost multiple fortunes, has been cheerfully telling me in great detail for several hours about how he was inspired by former Conservative minister Michael Gove to use snails to cheat local councils out of tens of millions of pounds in taxes.

London Centric

Sadly, in 2021 the whole thing was found to be a sham.

Which is a pity.