The Club for Growth provides the back story:
Scott Garrett, along with several other brave House members, have been offering amendments to the Labor-H[HS] spending bill to strip it of pork. Yesterday, Garrett sought to remove a pork project inserted into the bill by Rep. Don Young of Alaska. You might recall that Young was one of the authors of the infamous "Bridge to Nowhere" earmark. Also recall that Young is a three-time winner of the "Porker of the Month" award.
Of course, Young was predictably upset that Garrett would go after his beloved earmark. He issued a not-so-subtle threat by saying, "And like I say, those that bite me will be bitten back."