
Hi philly
It sounds as though you've tried a few possible options but perhaps not stuck with one or any long enough to get it working ;) The dogs need to know, through learning, that this behaviour is unacceptable and has a consequence.
IMO you should immediately remove them from the room for some time out- it may not work the first or fifth time, but be consistent and firm with them and the penny will start to drop. The dogs have to realise that barking means something - the message is entirely your own choice :)
(a) being removed from the room and away from you - so boring
(b) being removed from the room and getting a treat in another room - so rewarding
I'd go with (a) because if you mis-read or mis-time their response you may well encourage the problem you're trying to stop! Positive and reward based training is generally always my first port of call but when you have a pack - and 3 dogs is undoubtedly a pack! - then it is more tricky to use a reward based method for many elements.
To clarify, there will still be a reward in store for them - just not immediate :) The reward comes when they are quiet, calm and allowed back into the room with you. If this then starts up the same behaviour again, banished to the kitchen or wherever - and start again :) Dogs aren't stupid but they don't reason in the way humans do so only by repetitive actions or commands on our part do they eventually realise what we mean.
All behaviours are habit forming - whether good or bad. To break a bad habit we need to educate them with the habits WE form - i.e. in this case, exclusion until WE are satisfied the dogs will behave.
My dogs are not allowed to be in the same room as the window cleaner is working on - they would all go nuts LOL - so do I have perfect dogs? Definitely not! BUT I try to find ways to manage behaviours that I am not able (for whatever reason) to erradicate entirely. They occasionally will bark at the sight of passers-by or dogs from the lounge windows and a firm, mid-loud
'Nuff is sufficient to put paid to that but I'm well aware that wouldn't work with the window cleaner :-D
> I cant understand why they insist on doing this as they are otherwise very well behaved
they insist because they can - and they are enjoying it! The fact they are otherwise well behaved proves that you're good at assessing, training and controlling them so take a deep breath, relax, don't get yourself all wound up and casually observe their behaviours individually :) You'll almost certainly find that one starts the others off each time for example and that often at least one is barking without having a clue as to why!
HTH,
regards, Teri