Lyme disease is a bacterial infection cause by being bitten by an infected tick. Ticks are insects that live in areas of deep vegetation and climb on to animals and humans that brush past. They feed by drinking blood. If a tick has already fed from an animal with Lyme disease, that infection is also passed on to humans if they also bite them. Not all ticks carry Lyme disease, but if you do notice becoming unwell after being bitten, or spending time in an environment where ticks thrive, it is important to see a doctor.