A tip I learned from a book years ago-

Fatten your crawlers up before use!

Damp newspaper layered over the worm bedding, with a little weight on the lid to compress it onto the bedding, helps force feed crawlers moisture.

You can also put crawlers in a bucket of ice water in the fridge overnight. They don't drown as long as the water is 42-45 degs or so. Its a quick way to have MUCH fatter, tastier looking crawlers in a short period of time.

Seriously. Try it! Cold cold water, dunk the worms over night in fridge. They suck up moisture and are much, much bigger in 24hrs.