Really the only way to know is by being tested. They have a series of tests using blood work, glucose testing, sometimes urine tests. I've never heard of anyone having ants crawling around the toilet, but if you are spilling sugar into your urine (you may actually be able to smell a sweetish smell) than that's a pretty sure sign that your blood sugar levels are at least high. The fact that you drink sweet drinks doesn't imply that you are diabetic. Unless it's because you're all of a sudden EXTREMELY THIRSTY, like you can't quench your thirst, (but usually one would tend to reach for water because it's a sign of dehydration sometimes caused by the next symptom), which is a symptom or hyperglycemia (high blood sugar) some other symptoms are having to urinate more frequently than usual (in short this happens when the kidneys are overwhelmed and can't filter the glucose back into the blood stream, they will pull water from your bloodstream to try and dilute the glucose, which keeps you running to the restroom), with very high levels of blood sugar, you may become very agitated and even aggressive, tiredness and weakness, sudden weight loss (in type 1), or a gradual (more unnoticeable) weight loss in type 2, blurred vision, dry or itchy skin, if you have wounds or bruising that takes longer to heal than normal ( especially in your feet) and also one of the first symptoms one will notice is tingling in your extremities, mostly hands and feet. This is cause from consistent high levels of glucose, and it causes nerve damage. This is called neuropathy and if you're experiencing it you should go to the doctor. All in all, diabetes is pretty complex and there are a lot of factors involved and what not. It's just best to check with a doctor if you're concerned. Sorry it was such a long answer, but I love this topic. It was one of my favorite patient teaching things. Diabetes runs on both my mother's and father's side so naturally I stay curious about the subject.