Oh, what cuties! I have a strong case of chick envy. No chicks for us this spring (boo hoo).
Careful, though, when they're little like that they can squeeze out small openings. The spaces in your wire look large enough for escapes. You can block the bottom two feet of the run with something solid, or something that has smaller openings. Later on, this will also help to deter reach through predation later on.
Something else that I've also found helpful is to offer some kind of visual cover inside the run. You and I know that the wire roof makes the chickens safe, but they don't know this. They seem to feel more comfortable with something to hide under. This can be anything from a shade cloth to leafy branches stuck on top of the run. I recycled some old bamboo shades by laying them flat on top of one of our runs; our flock seems much more comfortable in the run during the winter when the trees that hang over the run have no leaves on them.
