Most peanut butters that are in supermarkets don't have oil rising to the
top--they are of one consistency. This means that they have "Hydrogenated
fat", which is very bad for your health--like butter, or beef fat.

You can usually find at least one brand that has the oil floating on the top.
(On the West Coast that brand is "Laura Scudder". ) This is the healthy,
good kind. No "Hydrogenated fats or oils". You can stir it up and store it in
the fridge, where it will stay mixed. Or you can leave it on the shelf, and
give it a stir each time you use it.

Do your children, and yourself, and buy a peanut butter that has the oil
"separated", or floating on top. A nuisance, but so much healthier.