Victoria Clare writes:

A frog has taken up residence in a corner of my greenhouse under a pile of
old pots.

Should I evict him, or can I keep him as a handy organic bug-killer?

I find so many amphibians in my greenhouse that I sunk a deep tray in
the soil underneath one of the racks, added some pondweed and a couple
of pond snails, and keep it topped up with water. There's usually at
least one inhabitaant during the warmer part of the year, and very
little slug damage to anything...

Anthony