Actually it isn't. Irreducible complexity is something else entirely. Irreducible complexity is a prediction of the theory of evolution and was made in the early 20th Century:
Muller 1918 pp. 463-464 writes:
"... thus a complicated machine was gradually built up whose effective working was dependent upon the interlocking action of very numerous different elementary parts or factors, and many of the characters and factors which, when new, were originally merely an asset finally became necessary because other necessary characters and factors had subsequently become changed so as to be dependent on the former. It must result, in consequence, that a dropping out of, or even a slight change in any one of these parts is very likely to disturb fatally the whole machinery; for this reason we should expect very many, if not most, mutations to result in lethal factors ..."
(emphasis in the original)
What evolved first, the animals eyes to see the prey, teeth to chew the prey, stomach to digest the prey, ect.?
Darwin's theory was inspired before he realized how complex cells are. It is outdated and should not be taught in school.
Agreed. We should teach the modern theory of evolution instead.