PETER THEOBALD says:
Whilst I personally only ever employ one whirly, there are occasions where two can be beneficial. These are usually when the pigeons have taken a bit of a hammering, and are becoming wary of traditional decoy patterns – or seeing one whirly working on its own.
The theory goes incoming birds are confused when confronted with two machines as they can only focus on one at a time. I’ve found they need to be set at least 10 yards apart for this ploy to work. I haven’t tried it but I daresay you can run a couple of whirlies quite easily off a heavy duty battery but, obviously, battery life will be reduced as a consequence.
That said, the biggest downfall, of course, is having to lug the extra weight of a second machine all the way out to the hide and back again!
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