European Nightcrawlers are a thick, tough worm. They are easy to thread on a hook and they stay there because their skin is so tough and they are so strong. They can be refrigerated and will maintain excellent condition for up to 3 months. Once purchased, these worms are really easy to look after. They will survive so long as they are stored below 25 degrees. The easiest way to keep them alive is to pop them in the fridge or an esky. And lets face it. There arent too many fisherman that go fishing without an esky!