Ants do not carry any diseases that can be spread by humans except for food-borne illnesses. Ants can have E. Coli and other diseases on their body and can be spread onto food. These diseases can be E. Coli, Salmonella, and Shigella, which will lead to nausea, vomiting, and flu-like symptoms. If you have ants on your food, or on your surface, please wash or throw out food, so you will minimize your risk of sickness.
Some ants such as Fire Ants carry venom and will sting rather than bite. These stings will leave a burning sensation, give off redness and swelling, itching, and pumps that start to blister like pimples and zits. These stings can cause allergic reactions in individuals, which can lead to hives, dizziness, and difficulty breathing. While extremely rare, it is possible to have life-threatening symptoms such as anaphylaxis, or shock.