Hello! We have 2 Silkie Bantams and 2 Cochin Bantams, and they are 5 weeks old. We have built our chicken coop (pics below) but won't be able to build the run just yet. Looking at the picture of the coop, is there anything we need to do to make it safe against predators? Also there seems to be no ventilation inside the coop part, I posted pics of it below also. Is there anything we need to do for that? There will be nothing but dirt underneath it, we were thinking about using sand but the only sand we have seen is the play sand sold at home depot. Is that the right sand? We are wanting to try and get this done today, so ANY and ALL tips and advice is definitely needed and welcome! Thanks in advance!