RE: .22 calibers legal for night hunting
I would think that if they were harming your livestock you could take them at any point.
Heck, even here I think you can shoot deer out of season if they are seriously damaging your crop.
And a lot of times here it seems that the laws might be relaxed a little on private land. The same might be for your state. Read the laws carefully and look for loop holes and when you have a doubt, ask somebody knowledgable of the law.