because their wings is just made by wax and if Icarus fly near the sun his wings will melt.
Daedalus was the greatest inventor and son of the war goddess Athena in Greek Mythology.
Icarus was the beloved son of Daedalus.
While being imprisoned in the everlasting maze and heavily guarded labyrinth, the intelligent Daedalus planned an escape along with his son by making a makeshift wings made of metal scraps and wax.
They successfully escaped from the labyrinth, along the way he warned Icarus not to fly too high, so that was on his wings will not melt and not to fly too low so the wings will not be destroyed by the sea.
Unfortunately his son Icarus flew a little too high near the sun, causing the wax on his wings to melt and then plunge to his early death.