I do not doubt any of what you have said, but isn't it possible that you observed or saw an ant the day before and then while dreaming your subconscious filled in the blanks?
Like I said, I do not doubt that you possess the gift, but it is always interesting to understand the role the subconscious may play with phenomena like this.
Personally I get a lot of feelings of deja vu with situations and events that are occurring for the first time. And when I get that feeling I literally see a "double" of what I am in except the details are not all the same. So I end up asking myself if I was somehow here before in a non-physical, possibly spiritual way (not spiritual as in religious). If somehow asks me how I know it is deja vu, I can not describe it because wherever the feeling comes from, it is unlike anything else I know.
I know someone who can tell you when it is going to rain simply because they get a feeling in their body. I know from first hand experience that he does not have access to a TV or Internet with which he could possibly "cheat" and considering the percentage of the time he is right (very high) with his predictions, I know it is some sort of phenomena. Whether or not you consider this precognition, it is certainly not able to be explained in any normal context. I have heard people say it has something to do with a change in the air pressure, but this man has done this in just about every kind of terrain (as in elevation) and climate you can find in the United States with no difference in his ability.