Rather than buy bags of designated rat food, I feed my critters a mix of basic human foodstuffs, supplemented by my own leftovers. Their diet should be mostly carbs (i.e., grains), and one of the cheapest ways to do this is to feed the little boogers a lot of oatmeal. I can't stand the stuff, so normally I just buy big canisters of whatever brand of rolled oats is on sale and feed them cold porridge for breakfast, but this week the supermarket happened to have packets of "fruit-and-cream flavored" oatmeal on sale. They like fruit, they like cream, and they like oatmeal, so I figured I'd pick it up and give them sweetened cardboard-sludge every once in a while as a treat.

They got "bananas and cream" today . They are adamant that this is not their beloved cold porridge. Don't get me wrong, they demolished it -- they just had to sniff it a lot first. They have a point. Given the smell of it, I'd say it's not "bananas and cream" so much as it is "isoamyl acetate and powdered non-dairy creamer". They like it fine, by which I mean I am not allowed to reach in and move the bowl without setting them on high-rat-alert, but it isn't quite the same.

Isoamyl acetate, while not quite on Derek Lowe's list of "Things I Won't Work With", is something a lot of chemists hate. Even the biologists, who think that adding menthol to their Formalin will make them smell less like death after a session of dissection, will often retch when confronted with banana oil. Isoamyl acetate is one of the major components in the flavor and scent of actual bananas, and making it is a common undergrad chemistry lab project -- it's a simple double-displacement reaction, and the reactants are isoamyl alcohol and acetic acid, which are both cheap and difficult to hurt someone with, no matter how much of a knob your lab partner is. You could probably manage it, but you'd have to snort them, drink the beaker, or very carefully orchestrate the concentration of the alcohol vapor under the fume hood and then take a Zippo to it, which is the sort of effort that ought to get you violently "excused" from your lab section anyway.

Banana oil is also unusually pernicious. I don't know why this is, but if you're around the stuff for any length of time, it'll get lodged in your sinuses, and you'll be smelling cheap scratch-n-sniff banana stickers for days. It's not as horrific as butyric acid or things with selenium, but you'll get heartily sick of anything you get whiffs of constantly for seventy-two hours straight, particularly if it also makes everything taste of artificial banana, which it does.

Feeding the rats non-dairy creamer isn't particularly bad for them, incidentally. It's a mix of vegetable oil (which they should have some amount of anyway, as it helps them keep their coats in good order) and milk protein/corn syrup/vanillin. As long as you don't make it a mainstay of their diet, it's no worse for them than feeding them the equivalent amount of cream. They don't think the powder is especially nommy, but they deal with it all right when it's in liquid form things like porridge or rooibos "chai" mixes.

The non-fat non-dairy varieties, I have my doubts about. I once ran across a bottle of something that claimed to be non-fat, non-dairy, low-calorie, low-carb "coffee creamer". I had no idea what the hell was in that bottle, but I wasn't about to ingest any.