How could I have caught lice?

From another person! As humans we are the host for 3 different kinds of lice: head lice, body lice, and pubic lice. Lice are wingless, bloodsucking insects. They are difficult to see because they are about the size of a sesame seed and they adapt to take on the colour of their surroundings. They are thought to spread through close contact.Pubic lice are usually spread through sexual contact.
From someone else. Lice are transmitted from one person to another by using a comb or brush.