Toys are more for entertainment purposes of our rats. Bruxing is what keeps their teeth short, mostly. Bird toys, hanging ones, are the best for rats, as they're made to be torn apart. Same with some small animal toys. If none of those seem interesting to your girls, you can try DIY toys with treats in them, as that will be the surefire way to get their attention. There's probably hundreds of videos and webpages dedicated to DIY toys for our little fuzzballs.
For treats, try organic baby food for rats. I've known puffs to be a HUGE hit with every rat I've had, and those are always high motivators. My boys love organic baby food that comes in those pouches or little cups. With seeds, please keep them at a minimum. Seeds are very fatty. Likewise with puffs. I've seen some people use organic peanut butter, but I always hear about people worrying if that'll cause their rats to choke. I'm not quite sure if that's true or not, and I keep forgetting to have my boys try peanut butter. Straight up organic yogurt is HUGE hit with my boys
Yogurt that can be licked up may be more appealing than yogie bites. Trust me, I've had some boys straight up reject broccoli, and then eat baby food that is just broccoli lol.
I think all fruits should be occasional treats. Fruits have high sugar values, which can be bad for anyone if they are consuming large quantities. Veggies provide a lot more nutrients, anyways.
Cereal can be a hit as well, but I keep it to corn flakes and Cheerios to avoid unnecessary sugar.