Spikes (maggots) are larva of the Bluebottle Fly and are about 1/2 inch long. When properly maintained in the supplied packaging, they can be kept for months. They are also great for panfish and trout. For best results, spikes should be refrigerated in the ziploc bags they are shipped in at about 33-38 degrees F. Like waxworms, spikes do not require any food. Remove any dead on a regular basis and keep the bedding dry.