What can be done to control ground hogs? Are there any IPM approaches?
Ground hogs can be difficult. Is this in regards to a backyard garden? The most effective ways, though not always the easiest, are exclusion and live trapping. Penn State has a fact sheet here: http://pubs.cas.psu.edu/freepubs/pdfs/uh092.pdf
Often, they have to be dealt with in a lethal fashion if they are really causing unacceptable damage.