There are several things I'd like to point out:
~The cage seems to be a bit small for the boys, A single critter nation would give them plenty of space to play and sleep, is much sturdier, and will be much much easier to clean. The cage you have now looks like it can be knocked over easily, and only has 2 small doors. A CN will open completely so you have full access and be able to clean easily. The bars of a CN are also much sturdier.
~You should either get them a new cage, one without wire floor (I recommend a CN, you can look on amazon or possibly some buying/selling apps and websites) or put linoleum tiles over the wires. The wires are hard on their little feet, can cause infections, and bumblefoot. Imagine waling on wire like that all day, its no fun!
~I see a plastic ball next to the cage, these are never a great idea for rats, toes can get caught and I believe it scares them overall. The best way to let your rats out Is in a playpen (I made one from broken down very tall cardboard boxes, taped and clipped together) or a rat proofed free roam room, I use my bathroom, and fill it with cardboard boxes, tunnels and all kinds of fun toys and let them go nuts!
As far as the cage interior goes:
~They would definitely benefit from more interactive toys, try the dollar store for some cheap plastic baskets you can ziptie to the sides, plastic tunnels, rope toys for dogs hanging and making sort of a climbing maze, hang some foraging toys (either for birds or small animals) and stuff them with treats (you can also make your own by cutting a toilet paper roll into rings, and stuffing them into eachother to make a ball.) Here is a great video on DIY toys:
~The wheel that you have is a big concern for me. Rats need a 12 inch wheel, without and holes. It needs to be solid plastic so no toes get caught.
~The hide/hut that you have is not a good one for rats. That Ecotrition (I believe that's the brand) hut uses honey to make the hide sweet, when it actually has harmful ingredients for rats. Please replace it with a space pod or igloo ASAP
~My girls love to sleep in hammocks, if you're good with sewing you can look up really easy tutorials, I've also made them out of modified clothes, you can buy them as well.
I think the main thing is that the boys are in a new environment, but they don't have much to do. I would recommend investing in a single Critter Nation, and filling it with all kinds of interactive toys!