Are shady zombies supposed to travel in packs?

I’ve noticed that for some reason shady zombies always travel in groups. I don’t see anything on the wiki about them actually exhibiting herd behaviour but everytime I see one there always seems to be another very close by.
No other zombie seems to have this behaviour. Is that normal?

It’s probably because they have such good night sight, they can spot things other zombies can’t and react so they’ll tend to cluster.

that is possible, since i’ve seen zombie herds cluster around shocker zombies because it was the most visible
but that still doesn’t quite explain why even in the daytime they cluster

Chasing stuff in the night perhaps (other then you I mean) once they hit daylight they’ll go blind again and lose the target.

These are only guesses mind you.

GROUP_ZOMBIE in monstergroups.json contains the following line:
{ "monster" : "mon_zombie_shady", "freq" : 30, "cost_multiplier" : 15, "pack_size": [4,6]},

So yes, there is a chance for shadies to spawn in packs.

Interesting, I’ve seen some weird stuff spawn before and this would explain some of it.