Do Zombies start to eat the survivors when time or when turns have passed?

[The Purple Pantywaist]

Hi!

I just started playing the game, and witnessed, that the Zombies start to infect the survivors eventually.

But do they start after time has passed (so you are supposed to be quick) or do they start after you have made some turns (so you are supposed to make efficient moves)?

Thanks!

[[BootSnake] DFS]

After you make a certain number of moves. For regular zombies its between 4-8 moves before they start doing their little infection dance.