I am wanting to build a training pen at my house and was wondering what the average wire that you see used. I was at first thinking 4'-5' 2x4 welded wire but then I am not sure about that. That will be costly for a decent sized pen. Then I am afraid that a rabbit might slip through 2x4? I was thinking that I might could try and find some chicken coop style wire with the roundish holes about 3' high, won't last as long as the 2x4 but it will be alot cheaper to make bigger pen. What have you used in the past or have seen used for a training pen?