The Law states that grey squirrels are ‘vermin’, and as such can be killed. Are there any conditions for this? Like, they are actually causing a health hazard or something? Cos they ain’t bothering me or anyone else.
No conditions, they are a health hazard and they will be systematically destroying the local woodland, that’s their job.
You’ve not mentioned trap types, while the Fenn type traps (springy large mousetrapy) are legal for fluffy tails their necks are a bit strong for them really. The only redress you have is to ensure he checks them twice a day and that they are covered (in a tunnel), and don’t catch cat’s legs etc.
Standard practice is to use cage traps and despatch in a sack humanly breaking their necks or gassing. Neither of which I’d recommend without some training. An airgun is the best method for amateurs, in a cage that is not shooting them out of trees etc. Stick the barrel in the cage and they’ll bite it making things straight forward.
Planning stuff like this can be fun but honestly can’t see him getting a kick out of it for long, despatching and disposing of dead animals gets old quite quickly.
And you’re right about them just breeding to replace ‘the fallen’.