All humans have a unique set of fingerprints on the tips of all 10 fingers. In addition to humans, several other animals have fingerprints as well. All primates have fingerprints, including monkeys and apes. One interesting fact about monkeys is that some monkey species also have unique prints at the tips of their tails.
Humans have fingerprints for a practical purpose --- the ridges on the tip of the finger that make up the fingerprint pattern allow a person to grab and hold onto items. Some students have a hard time believing that the tiny pattern on the tip of their finger is actually that necessary and useful. To prove this, have students lift a piece of paper with one finger. Then, have them try to lift it with the back of their finger --- they will quickly find it is impossible to do.
There are six main categories of fingerprint patterns. The first two are called the loop from right and the loop from left fingerprints. These fingerprints have a small loop pattern in the center that typically leans toward the left or right. An arch fingerprint has an arch in the center of the finger, while a whorl fingerprint is a curvy, circular design. The fifth category is the double loop, which is two loops on top of one another, like a yin and yang pattern. If a fingerprint doesn't fit into any of the five above categories, it falls into the sixth category of eclectic.
Human fingerprints are interesting and unique as they are formed during weeks 10 through 24 of gestation. The fingerprints a baby is born with are the fingerprints he will have throughout his lifetime. Fingerprints will only grow in size, but will not change in pattern. This makes fingerprints a useful tool in identification. Every person is born with a unique set of fingerprints that is not replicated or duplicated on any other person.