Calci worms roughly contain 20-40 times more calcium than other dried mealworms which you can find - which make them a great choice (especially during the fledgling season)
If soaked for 10-15 minutes the Calci-worms double in size which is thought to be easier for the fledglings and other birds to eat, and although when the worms are dried they only loose the moisture, so this is a great way to replenish them and get them plump again.