I have dug dozens and dozens of sand shrimp and here's what works for me.

1) Always handle the shrimp gently. (Use a clam gun instead of a shovel. Gently rinse the sand off the shrimp with salt water. They are very fragile critters.

2) Store them in a ventilated Tupperware sandwich container lined with two layers of absorbent paper towels, and a damp towel on top. (Shrimp excrete a liquid (urine?) that kills the shrimp that are on the bottom. If you really want them to live for more than a few days, change the paper towels every day or two.

3) Refrigerate at 35 to 40 degrees, or store in a cooler on ice. *(The shrimp live longer if the containers do not come into direct contact with the ice.)

***Don't forget to change the towels!***

I have been able to keep shrimp alive and feisty in the fridge for over two weeks, and in a cooler for over a week using this method. It takes alot of work, and alot of time to dig your own shrimp. It is a bummer to find that half have died over night. This method has worked for me time and time again.

Hope this helps...DB