newby grit question

[auto5man]

my girls are about 2 months old and on chick starter, but about 2 weeks ago they started free-ranging all day long (daily) and seem very healthy/happy. Do I need to get them grit? Of course they peck and scratch almost every waking moment in my backyard (urban) and I'm guessing they have found some natural grit. I have given them crickets for treats and fruit, but nothing more solid than that. Will they find enough small rocks in my backyard?

 

[ChickenAl]

Usually they will find enough grit, but it is a good idea to provide some supplemental grit near their ration of feed.

 

[waitin on eggs]

Mine free range also, however i provide self service containers of grit and oystershell/ egg shells intheir coop and i refill it often.