What's that white packing material around my spring mason bee cocoons?

What's that white packing material around my spring mason bee cocoons?

What's that white packing material around my spring mason bee cocoons?

Spring mason bees hibernate as adults inside of their cocoons and the warmth of spring tells them it’s time to wake up and emerge from their cocoons. To help the mason bees stay asleep in their cocoons we provide them with an ice pack that keeps the cocoons cool during shipping.