Combine the chicken, cream of chicken soup with the sour cream. Mix the crushed crackers with the melted butter and poppy seeds. Combine 1/2 of the cracker mix with the chicken mix. Grease a 9 by13-inch casserole dish. Scoop the ingredients into the pan and top with the remaining cracker mix. Bake at 350 degrees for 30 minutes or until warmed thoroughly. Serves 4-6 people