Libraries can be dirty. Patrons handle books and other materials carelessly and contaminate them with body fluids and germs. Children can be especially careless in this way, and pets are often unclean. But adult patrons are most often to blame for causing hygiene problems in libraries. Library washrooms can become very dirty. Pigeons can soil library exteriors. There are concerns about the effects of a pandemic in libraries. Solutions include good janitorial service, asking patrons to take proper care of the library materials they use, encouraging hand washing, and the use of trash receptacles.