Like most animals, birds don't naturally overeat. Of course, if you give them a diet of high-fat foods, and don't provide ways for them to get exercise, they will become overweight. And, if you deprive them of their favorite food — say, if you're trying to convert them to a pellet-based diet — and suddenly present them with a whole dish of sunflower seeds, they'll likely stuff their faces. In fact, in this case, there's a chance that they might eat so much their crop would get impacted. This means the crop becomes too full for normal food passage, and it can be life-threatening.

Peanut did not just have an over-full crop! But he did get at least one too many sunflower seeds from a friend. He stood very still on the table after his little feast, feathers all puffed up, almost asleep, gurgling a little every now and then. I've seen this before so I wasn't really worried. Still, I was pleased to see Peanut finally shake himself, poop, and climb up my arm to his usual spot on my shoulder.