It is normal for there to be a lump, usually quite red, after a tick is removed. If there are any parts left, i.e .mouth, head etc., the body seals them off and they are rejected with the scab. Any tick bite, however, no matter how the tick is removed, will need to be watched for signs of infection. I am a groomer and I pull between 15 and 20 ticks off dogs daily with my fingers. The swelling is from the irritation of the bite as well as the digestive enzymes the tick uses to thin the blood.