I cast out a ledgered cube of meat and in the clear water I watched a barbel rush towards it before it had settled - I thought this is going to be quick - but the barbel inspected it and backed away.
The barbel seemed to be alone in the pool and over the next 20 minutes came and examined the meat a couple of dozen times - didn’t touch it, no indication of it’s presence on the rod tip.
I’d given up hope of it taking the bait - but interesting behaviour to watch. Then it grabbed the bait and tried to steal the rod! Makes you wonder what is really going on in this normally hidden world.