Get a five gallon bucket and fill it half full of water then sprinkle enough sunflower seeds on the top to cover all of the water. Place a plank up to the top of the bucket and when a ground squirrel goes up the plank he will see and smell all of those seeds and jump in. He will not be able to reach the bottom and jump out so he will drown and sink to the bottom and the next squirrel will come along and do the same thing.