We all know what litter is, it's that little bit of rubbish, cigarette ends, crisp packets and drink containers, that are carelessly dropped on our streets.It's a problem because:It's illegal. It costs taxpayers' money to clean it up.It's unsightly. Litter is a sign of a neglected neighbourhood and is associated with increased levels of crime and the fear of crime. Litter also discourages investment and new businesses from moving into the area.It's unsafe. Litter attracts vermin such as rats, flies and other disease carrying pests. As well as being unhygienic, litter can be dangerous, and broken glass and other rubbish can cause injury.