If a woodchuck is inside, it will come out to feed during this period. Observing the woodchuck enter the burrow before gassing is best. Trapping woodchucks alive can be an efficient way to capture nuisance animals. Cages can be set along woodchuck paths or near their holes, baited, and left to do their work. All you have to do is check the trap regularly.
Woodchucks are primarily active during the day.
So closing the traps at night will reduce the risk of capturing skunks or domestic cats. If this should happen, these nontarget animals can usually be released from the cage traps unharmed. I don't recommend leg-hold traps in urban or suburban areas because of the possibility of injuring nontarget animals. Good woodchuck baits include apple slices and other succulent fruits. Be sure to place the trap in the shade, as woodchucks are sensitive to temperature extremes, and heat exhaustion will cause a trapped animal undue suffering.