One of the most common myths about warts is that you can catch them from toads. In reality, warts are usually spread through contact with another person, not an amphibian. And what causes the infection? Human papillomavirus (HPV).
HPV is usually discussed in relation to sexually transmitted infections, but there are around 100 strains of the virus. Only some of them cause warts, which can develop on the genitals, hands (palmer warts), bottoms of the feet (plantar warts) and just about anywhere else. Kids are more prone to them because their immune systems are immature, but children's warts also seem to disappear more quickly.
Once the virus takes hold, blood vessels root in the wart and begin to feed it the oxygen and nutrients it needs to grow. You can see these dark pinpricks in the wart if you look closely.
To get rid of warts before they spread, the first step is to kill the virus.