goldfish that picks up!

Question
my one common goldfish loves to pick up his rocks in his tank and move them from one place to antoher and put them in his mouth and  spit them out why does he do this?

Answer
Hi Micah,
 Many fish move rocks around.  They do it to find food that is under the rocks, to build territorial areas, to make mating and courtship areas and other reasons.  It is amazing how many rocks they can move if they are determined.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>