Greetings, Sorry for posting but noticed a few particulars about these plants. Fruit rot is mostly defined by a calcium deficiency, however saying that, there are some questions left unanswered as to how much you water and the nutrients you feed it. I noticed a bit of browning on the edges which is usually a potassium deficiency but I don't see any curling. I think the ants and other insects feeding on it can be explained by the plant not being able to produce its natural defense, the capsaicin. The ants will treat it as a plant with no defenses. It is hard to see from the photo but the soil looks tamped and dense, almost like a clay / sand consistency? The large L shaped cut on the leaf says a caterpillar had lunch there. First thing I would do is cut off a piece of the fruit that is not rotted and taste it, it sounds gross but I bet it taste like cucumber with no heat?Â