Seal Around KJ in Counter

Hey All,

I built my KJ into my little covered area and made a cut out in the concrete counter for it but purposely left a little gap around it. Well, I have quickly found that being by the water, my rat friends love to stop by after cooking on the gas grill and get in the structure via the gap around the Joe; any ideas how to fill the gap?

Terrible pic but gives you an idea of what I have.