Caitlyn Yordle trap at base.

I was playing a normals and i was going to put a Yordle trap in front of the 3 tower in mid(The inhibitor tower) and i don't know if its not a bug or not, but when i placed it close to the edge of the entrance it became invisible. So don't know if its just a bug or something intentional. Every time someone walked closed to it they would get hit by it.