Immediately after Dorian's entry one can already be seen toddling around near the gates. They will appear like that through the day, just walking across the grass. They don't particularly look like they're planning a cunning attack. They're just walk around and look. They ignore animals, and spiders for the most part (the most part, if one is bitten accidentally it will turn and follow the spider off through the trees). But the moment it sees a village citizen, even through the slats of the fence, it will start in their direction and follow them through the fence.

It's a good idea not to let them get too close, or people will get hurt/there will be fence damage that has to be repaired before nightfall.