After failing on the last day in Zombie Massacre (at least on Gasoline), the level does not reset.
So when day 6 restarts, any webs that the spider had shot will stay on the ground.
This also applies to the ragdoll for the spider, if you lost the day after defeating it.
Edit: Didn’t realize that I took a screenshot of it.
I hope this gets fixed, sometimes if I mess up badly I like to suicide and start over. But the annoying webs are still placed down and I never bother shooting them.