The ones that I built myself I'll check every 7 to 14 days or sometimes longer during the "off season" They run on 6 volt gell cells or 9 volt batteries which last forever.

I just bought some wildview cameras that killed a set of C-cells in about 10 days (not sure because they were dead when I got there). No pictures either!!!!

I don't usually hunt the immediate areas I have a camera setup, but I if I plan to I'll take it out a month before the season starts. I don't think it spooks them, but I could be wrong you know!