Some ppl get "buck fever" worse than other ppl, almost making it a cause of stress. The last few minutes before the shot are very stressful in my book, and I know that when I am under stress, as soon as the source of the stress is gone, one of my reactions is to laugh. I am not laughing because I killed a stupid bird, or whatever, I am laughing because a stressful situation has come to a close. Heck, I am downright proud of myself for accomplishing a goal like that, and if my laughing about it offends someone, I gotta tell ya, I don't care.