Oatmeal is made of hulled oat grains – groats – that have either been milled (ground), steel-cut, or rolled. Ground oats are also called “white oats”.
Steel-cut oats are known as “coarse oatmeal” or “Irish oatmeal” or “pinhead oats”. Rolled oats can be either thick or thin, and may be “old-fashioned” or “quick” or “instant”.
The term “oatmeal” is also used in the U.S, parts of Canada and Australia as another word for an oat-based porridge popular in such countries made from either ground, steel-cut, or rolled oats.
Yes they can in small amounts. Just don’t feed them too much.
For more foods that guinea pigs can and can’t eat, check out our GUINEA PIG FOOD LIST.