Question: Do identical twins have identical fingerprints? And do animals have identical twins?

Edward Codling answered on 23 Jun 2011:

Identical twins would have similar fingerprints but not exactly the same. Our fingerprints are unique! This is because fingerprints are created by a combination of the genetic information you have and also the conditions you experienced when growing in the womb – these conditions will be similar but very slightly different for twins. Hence why fingerprints will be similar but not exactly the same.
http://multiples.about.com/cs/funfacts/a/twinfingerprint.htm

Many animals are born as twins (or even in litters with many brothers/sisters). An identical twin is when they develop from one zygote (egg) that splits and forms two embryos. However, as with fingerprints, the way an animal looks is determined both by genes and the conditions in the womb at the time (which each individual will experience in slightly different ways – e.g. perhaps one twin will get more food at a certain time). Identical twin animals may look similar or they may actually look quite different!

There is a famous example of a cat that was cloned (so it had exactly the same genes as its predecessor) but it looked quite different: http://en.wikipedia.org/wiki/CC_%28cat%29
This is because there is more to our appearance than genes – it is also down to the way we grow and develop and the environmental conditions at the time.