Joanna, there will always be a little 'spill over' of seeds when you feed the birds, but you can minimize it by putting out suet cakes in the winter (my birds love the Peanut Delight suet) and solid seed cakes the rest of the year.
I also suspend a little net circle under my feeders to collect the spilled seed that the birds fling around. So all that can help keep the seeds up off the ground so the squirrels and chipmunks won't congregate for a free meal.
