Plans for a building

I'm struggling a little with some mental planning and need advice from the peanut gallery. I use three chicken houses - two layers and one for turkeys used four months of the year. The north house is actually just a sectioned off part of the machine shed lean-to and the pen for it is right in my way. It was supposed to be temporary. One is made from pieces of an old grain bin and is a bit like a crock pot in the summer. I use it for turkeys. The "good" one is the original milkhouse with the pen along the south

I'm going to build the new house large enough to use half for new layers and half for turkeys. Here's my problem: what do I use to keep critters out from under it? I am planning on setting poles cemented in the ground and having a raised floor. The milk house has a cement floor but as much as the ground moves here it is kind of like a jigsaw puzzle with an added tripping hazard. For that reason I'm not going with a poured floor. Should I fasten sheet steel to the bottom of the outside joist and trench it in? Do I use welded wire?

I'm planning on having it nearly on grade but the land slopes slightly so one end will have access for coons and possums to get under. What say ye?

notjustair,You could set the poles,then dig down the depth of a tile spade between them for a footing.Then form both sides say with 2x6 - 2x10 (and use them later for flooring)say 6"-8" above where you want the floor to be,and pour concrete between poles.Nothing will be able to dig under your wood floor,plus it will keep the weather out(wind,rain and cold).