Something missing in their diet?

Question
When I let them out in the yard they dig and seems to be eating tree roots.  Are they looking for food or are they just playing?  They seem to like digging around a Sweet Gum tree.

Answer
Hello Tom !
I dont have a lot to go on!  Are you feeding your rabbit hay? Grass?  Bread? Clover? Carrots?  or Rabbit Pellets?  
If your feeding a comercial Rabbit pellet that is all your rabbit needs to be healthy.
But you can suppliment its diet with small amounts of fresh Veggies. only 1/2 a carrot. never feed lettuce or leafy greens they will get  the runs & get dehydrated.
the digging at the roots is  only normal rabbit behaivor. the roots may be tasty to them , but mostly they like chewing on stuff. try giving your rabbit a small block of wood or an empty corn cob, a pine cone, or even an alfalfa cube. they like to chew.
Good luck
Dan