I can get one of my hens to lay in the run, in an old cat house. The other refuses and convinces the other to be a rebel like her.
Mine have never layed under bushes/brush, instead wallowing out a depression in the center of tall grass, generally within 10 or 15 feet of an edge - the edge of a field crop, edge of my property, edge of a ditch, etc. One of my hens has a rather loud egg song, and the males hang around to guard during laying, so as long as you are home when it happens you should be able to figure out where they ar laying.
Right now mine are laying in weeds/overgrowth in my landscaping under my living room window, and I'll keep it overgrown until laying season is over. It looks like crap but it keeps them safe.
Update my AWOL guienea made it through the night, it was on a trailer right behind the coop this morning when I went to let them out. I have another concern, I sas on of the guieneas limping yesterday, couldn't tell why because I can't really get close to them. I know the only way to catch one is to wait till they are on the roost but how in the heck wil I know which one it is? I looked for markings or something different but all 10 look the same to me. I can only tell male from female. Thanks