Hi, we have openings behind our floor-level kitchen cabinet, and mice keep getting in through them. The cabinet's almost 2 feet deep so it's not an easy area to reach. I'm hoping if I just close the openings in the wood around the pipes, the open cabinet backing won't matter. That would leave me with one large round opening around the pipe there, and small gaps around the other two. I'm guessing I could use wood filler or something in the smaller ones, but not sure how to get something strong to go right up around the pipe in the larger one. Any suggestions? Thanks.