One of the dumb-arsed assumptions of the mousetrap non-game, (that atheists weren't supposed play), is that a mousetrap would evolve by itself. It's supposed to be an argument that an eye could not evolve, and yet we don't see eyes evolving by themselves and lying around in the environment.It is quite silly to think that an eye could evolve on its own. Without even one piece developing, the eye wouldn't work. It would be useless while evolving in previous generations and they would die out and we would find their fossils. Yet, we don't find their fossils.
Yes, if an eye evolved by itself, and we saw eyes everywhere, looking at things, without being able to eat, or have any reason to exist, then yes, that would be evidence of irreducible complexity.
No, an eye would be useless if it was just and eye, lying around in the environment.
An eye cannot evolve when it is detached from an animal, because it requires a blood supply, ovary, digestive system, brain, .... and well, a whole animal to be attached to.
By analogy, a mouse trap cannot just lie around in the environment, unsupervised, unbaited, and without motive.
By analogy, a mouse trap would have to be attached to a larger animal, such that the base of the mouse trap was perhaps the side of the animal, or its tongue.
If the original base of the mouse trap was the animal's tongue, then the base of the trap worked, without any other parts.