Yep I mix food for our three rats. I just don't care for most of the store bought rat mixes, as the rats seem to waste a lot of the stuff. Plus it's just easy and cheap really and I think the rat's like it (they are certainly all big enough LOL!) Here's a few links I used to make up my mix and one link of forbidden foods.
http://home.comcast.net/~aunty_bs_rattery/Rat_Diet.htm
http://www.tailspinzrattery.com/RATCARE.html
http://www.petratscanada.com/forbidden_foods.htm
I just mix it all up...store it in a big bucket with a tight fitting lid and keep it in a dry, cool cupboard. They get some of this mix every day plus fresh treats (whatever is handy). I give nice hard lab blocks as a treat plus bones to knaw on for teeth maintenance. They all get one slice of bread twice per week that's got olive oil dripped on it (3 share one slice), feed from hand. It makes their coats as soft as a baby rat and it's a great way to use up those end pieces that no one in our house ever eats anyways.
The initial outlay to make up the mix isn't too bad (use bulk bins and store brands to save lots) and it lasts for ages and ages. I just keep adding to it here and there and it never seems to run out and is constantly changing LOL. Just make sure everything in the bin is DRY so it won't mold (I still give it a good swish with my hand every day cuz I'm just wierd about mold LOL). My rats LOVE soya nuts in particular so I don't put too many of those in or they'd just pick thru for their fav!
The links for recipes are just a guideline. Get creative or buy what's on sale as long as it meets a rat's basic needs they'll love you for it and so will your budget!
The next things we are going to try are:
1) frozen peas in a shallow water bowl for fun and cooling in the summer
2) feeder goldfish in water for hunting and general funness (we won't let Ping the Beta fish watch that LOL)
~~Joanna~~