Wierd Glitch with spider spawners

I noticed this on a survival world, when it spawns a spider on a spider spawner, it also spawns a skeleton. You can hit the skeleton once but then you cannot anymore. They don't move or have any sort of movement. When I blocked it off with torches it got worse, I couldn't even move through them because of the update. I have to log out and then back in, and then book it to my stairs before I am trapped again.