The little ones are toys.

Not my experience as I said earlier.

Expect to pay around £150 for a good
commercial one. Excellent within large exposed spaces like barns, lofts
and yards enclosed by stone walls. Virtually useless elsewhere.


Interesting effects on bats and would be completely illegal to use if
bats were present. I'm totally certain (! :-) ) t hat no-one here would
even think of using them in such circumstances.

Yes I wondered about that. I thought perhaps bats used much higher
frequencies than the repellers, about 150 kHz and higher.

Peter Scott