Blushing is one possible sign that a guy likes you because blood rushes to the cheeks when a person is attracted to someone. Hovering or staying in close proximity to the person that the guy is interested in is another potential sign.
Men tend to have a more open posture when they are interacting with someone they like and avoid crossing their legs or arms. A man may also start mirroring body movements and gestures when he is talking to a person he likes. Another sign that a guy likes someone is if he always takes advantage of any opportunity for physical contact, such as arm patting or hugging.