"Beaner" wrote: "How do you put them onto a hook to use as bait?"Sarge""

Personally, I don't know since I would never waste one for bait. Bur I did
find this in a fishing article

In my experience crawfish work best if you pull the pinchers off if you are
going to fish them on the bottom. Otherwise they will crawl around and get
you tied up. If you choose to keep the pinchers on, keep the bait off the
bottom with a three way rig or bobber rig. Crawfish should be hooked through
the tail when used whole, or you can cut the tail off and then thread the
tail onto a hook.

I also found this article on bass fishing in New Jersey and it address
crawfish. http://www.njskylands.com/odfishbas.htm

Sarge