I love answering questions like this since this is what i want to do once i get out of school. If it is a small thicket then don't do a thing to the inner part of the thicket. Just go and bush hog a two pass ring around the outside edge. What this will do for you is create what is called a transition zone, which is just that, an area between two diff. habitats. These are the areas that have the prime natural browse that deer seek out, such as freshly popped up clover and tender shoots of grass. This will cost you nothing but the price of your gas and a little time. To keep the small tender shoots of clover and grass coming you might mow it a couple of times intermittently throughout the summer, this will also help to keep the fox tails and and such down along with the multaflora rose and briars that pop-up. sorry that this was so long but i couldn't think of a shorter way to put it! If you have other questions send me a pm.

Adrian