Bumper stickers are like stickers that you can put on your car's bumper to show off something you like or believe in. They can have funny sayings, pictures of animals, or slogans that express your beliefs, like "Save the Earth" or "Love is Love". You can buy them at stores or make your own. Some people collect them and put them on their cars until there's no room left for any more! Just be careful not to put them on the paint of the car or you might damage it.