5 things you should not feed your rat
Cheese is fine to give rats in small quantity's so only give it to them as a small treat every now and then. Blue cheese however is extremely hazardous to your rats as the mold in it is toxic.
It sounds like a nice sweet treat for your babies however licorice sweets contain glycyrrhizinic acid and glycyrrhetinic acid which can be toxic for a rats liver and can cause respiratory problems.
This applies to male rats only.
Oranges contain d-limonene which bind to a natural occurring protein in a male rats kidneys. The protein can build up and turn into cancer. It's probably best to keep your boys away from citrus altogether.
Onion is a debatable subject when it comes to rat food. It is believed raw onion can cause anemia to rats and give them an upset stomach. Rats can not vomit which means it would have to endure the suffering until it has made it's way through your rats system.
Fresh fruit is an excellent choice of snack to give your rats, however be cautious of leaving seeds in the fruit.
Apple, peach, apricot, pear, plum and nectarine are the worst culprits and contain a substance which will release cyanide once digested.