Sizzle N' Heat®, a squirrel-deterrent product. While this is not a squirrel-proof product, our studies showed it to be a very effective squirrel deterrent. While squirrels may still visit and feed at feeders, once they get a taste of the hot seeds, most will look for other sources of food. As with any Wild Delight® product, ensuring the best bird feeding experience is the #1 goal. So Sizzle N' Heat® is filled with the same highly desired ingredients birds love, with none of the filler ingredients.