The Guiro is probably the most common form of scraper seen today. All scraped instruments produce a sound when a stick (or other rigid object) is drawn over a series of notches carved into a gourd, bamboo, bone, shell, wood or some other material. They produce a distinctive rasping sound that varies depending on materials used.

The one pictured is made from gourd and is a combination of instruments. Besides the guiro scraper, this instrument is also a rainstick. When it is inverted small rocks flow over needle like sticks attached within the gourd and produce a rain-like watery sound.

Scraped instruments have origins as far back as the Stone Age when it certainly had magical/ritual significance. In some primitive cultures, it still holds this significance.
In it's simplest form it is a notch bone, but can be also an elaborately caved figurine such as the crouching tiger Yü used in Confucian temples. Some other examples are the washboard, frog scraper from Vietnam and the cog ratchet.

The sound of the scraper can be increased (amplified) by placing it over a hole in the ground or making a resonator for it. The gourd guiro is a good example of a scraper with resonator as the hollow chamber of the gourd amplifies the sound.

The bone scraper has been closely associated with hunting and erotic rituals and funeral ceremonies in many cultures around the world.

The lore and magic of the scraper has been experienced in every continent and has survived into our modern time. Whether it be the sound of a guiro or the rubbing together of two pine cones to keep time for dancing in Portugal, the scraper's distinctive rasping sound has a place in much of our music.

It is quite easy to make a scraper as they can be made from almost anything.
All you need to do is to cut some notches into an object and then rub the notches with another object.

One of the educational values of making these would be to experiment with the different types of sound produced by varying objects. An example would be to rub your scraper with a stick, a thick piece of wire, and a thin piece of wire or with something soft. Thickness of the notches and the rubbing object would also effect the sound. All of these would produce differing sounds that the children could easily differentiate. You may find some children prefer one sound to another.

These sorts of lessons can lead to all sorts of discussions about sound and music.