We are new chicken owners, sharing our small backyard with 4 chickens, and we have quickly found out they love mulch! Mulch is everywhere! We are taking out the mulch and replacing with rock. I know we need larger rock. My question is how large? Will the rock in this picture work, or does it need to be more like 2”-4”? I know they can be strong, however there is grass that they can forage in...hoping when we replace the mulch with rock that they will find the grass more interesting than the rock. We’re ready to tackle the project and order the rock, I just want to make sure I pick a big enough rock. On a side note we may have to use pea gravel in a very small area, (along with larger rock in the main areas) any experience with pea gravel and chickens?