What size is your coop? Store bought coops are notorious for over-rating capacity.
Ditto Dat^^^ coop size in feet by feet will help us understand.
I put up a separate roost for the younger generation...and block off nests an hour or so before roost time to 'force' them to use roosts.
Sleeping(and pooping) in nests is a bad habit you want to break asap.
Your birds may be close to lay, but I wouldn't worry yet, it can be hard to wait.
If you are free ranging they may be laying out in range area.
Free range birds sometimes need to be 'trained'(or re-trained) to lay in the coop nests, especially new layers. Leaving them locked in the coop for 3-4 days (or longer) can help 'home' them to lay in the coop nests. Fake eggs/golf balls in the nests can help 'show' them were to lay. They can be confined to coop 24/7 for a few days to a week, or confine them at least until mid to late afternoon. You help them create a new habit and they will usually stick with it. ..at least for a good while, then repeat as necessary.
Signs of onset of lay---I've found the pelvic points to be the most accurate.
Squatting:
If you touch their back they will hunker down on the ground, then shake their tail feathers when they get back up.
This shows they are sexually mature and egg laying is close at hand.
Combs and Wattles:
Plump, shiny red - usually means laying.
Shriveled, dryish looking and pale - usually means not laying.
Tho I have found that the combs and wattles can look full and red one minute then pale back out the next due to exertion or excitement, can drive ya nuts when waiting for a pullet to lay!
Vent:
Dry, tight, and smaller - usually not laying.
Moist, wide, and larger - usually laying
Pelvic Points 2 bony points(pelvic bones) on either side of vent:
Less than 2 fingertip widths apart usually means not laying.
More than 2 fingertip widths apart usually means laying.