The Keep Britain tidy group say people aged 13 to 16 are the worst litter bugs.

And their research shows many teens think people who use bins are "geeks".

The group hope their shocking "Did you do it?" posters will make litter bugs think again. They feature a website address with terrible images of hurt animals.

Over 69,000 animals were treated for injuries caused by rubbish last year.

One dog had its tongue cut off by broken glass and a baby hedgehog was strangled by a plastic bag.

But the group say teenagers will only pick up their rubbish if they are paid to do it or bribed with a day off school.

Don't feel guilty

They say their research shows:

• Teens think their schools are swamped with rubbish
• Teachers don't punish people for dropping litter because they do it too
• Most common things dropped are crisp packets, sweet wrappers, bits of paper, cans, cigarette ends and gum
• Litter lessons were "boring".