When a woman has hard nipples, it usually takes place in cold office buildings. It refers to the thermometer that pops up when your turkey is done cooking

When you eat dirt for the first time and leave your family to build a shack in the woods

An expression to point out that a female in the room has erect nipples. Typically used for a woman with particularly large nipples like those of a temperature indicator on a turkey in the oven that pops up when the bird is done.

When a girl has hard nipples.