A Cooper's Hawk has been trapped inside Dillon Hall at the University of Windsor since Thursday.
Students spotted the bird and immediately called Phil Roberts, president of the Essex County Field Naturalists' Club.
A pigeon was also spotted in Dillon Hall, but has since been set free.
Although it's unknown how the hawk entered the hall, Roberts figured it chased the pigeon inside.
On Friday afternoon the university closed Dillon Hall and called in Bob's Animal Control to catch the hawk.
Ted Foreman works for the company. He said he's caught all kinds of animals before, including hawks. He planned to catch the bird in Dillon Hall using a cage of pigeons as bait.
"The pigeons will be down here," said Foreman, pointing to a spot on the floor of Dillon Hall. "And I have a net gun that shoots an air cartridge like a paint ball gun. He comes on there and I shoot him with that. And soon as we catch him, we run him outside and let him go back in his same environment."
Roberts said the hawk could survive without food or water for about a week, depending on its condition.