Heat Advisory: If temperatures in your area are above 85 degrees, we strongly recommend adding a cold pack and opting for a FedEx (1-2 day) shipping service. Fresh, healthy, fat feeder worms delivered direct to your door! Size: Medium (1/2") Live Mealworm Guarantee: Worms are insured if FedEx Priority Overnight shipping service is selected at checkout and the package is received upon delivery. If overnight shipping is not selected at checkout, the customer assumes all risk with no exceptions. View our full terms.