Originally posted by Malhorme:

But don't. You have a entrails farm at your disposal. Rebuild the house containing the spawner, make yourself some openings to shoot inside and you also have a archery training zone,

This right here, sausage factory. Place stone flooring over the spawner to protect it though, they'll tend to destroy it themselves while trying to bust out. A core wood log on the floor with a single unit high gap above is the perfect hole in the wall to stab their knees through.