The sensation of the tip of the thumb on the left foot sometimes seems like ants biting it, considering that it may be caused by discomfort in wearing shoes, peripheral neuritis and other inflammation. 1. Discomfort in shoes: If you walk in ill-fitting shoes or play sports for a long time, resulting in poor blood circulation in your feet, you may experience a tingling sensation in your toes like an ant bite. 2. Peripheral neuritis: Peripheral neuritis is an autonomic dysfunction disease of the distal limbs caused by drugs, chemicals, heavy metals, alcoholism, etc. Long-term alcoholism, cold environment and decreased immunity are the main triggering factors, and the distal limbs involved will have abnormal sensations, such as pins and needles, burning, tenderness and ants and other symptoms. As there are many factors that cause the left thumb to feel as if it has been bitten by ants, it is recommended to go to the hospital in time for diagnosis and targeted treatment after clarifying the cause of the disease, so as to avoid aggravating the symptoms of the disease.