A 4-year-old, Jack Bailey, from Wheaton discovered it.
His sister noticed it had blue eyes. The family took pictures of the cicada and then released it back into the yard.
Later, they discovered how rare blue-eyed cicadas are, so they found it again.
It is now the first blue-eyed cicada in the Field Museum's collection, which is over a century old.
The insect has rare mutation that is "one in a million," experts say. The mutation causes cicadas red eyes to be gray-ish blue instead.
The cicada is on display at the museum. More information about how to see it can be found on their website's event page.