Will a droppings pit let in critters?

[LocoPollo]

In my new coop I am thinking of making a pit below the roosts so the droppings can fall to the ground below. Of a 10'x12' coop, a 10'x4' area would be unfloored, so that three 10 foot roosts above could just let the chickens poop directly to the ground below. I was going to have a three foot wall in front of the pit, separating it from the rest of the coop floor, and the roosts would be higher than the wall and over the pit. At the top of the wall I was going to put down 1 inch wire mesh for the droppings to fall through. With this setup, am I in danger of letting critters in through the 1 inch wire mesh, even though it will probably be four feet off the dirt ground?

 

[Omran]

Just make sure you put really heavey duty welded wire and some cloth mech for smaller preditors and I think will be perfect.

 

[LocoPollo]

Yea I could put something like fence wire at the bottom and then a finer mesh at the top. I am hoping rats won't be able to get in through the mesh.