Mob Travel Habits

Is it just me, or do mobs (specifically monsters) tend to travel in groups of two or three, rather than alone? I've seen this a lot in my travels amongst the cosmos, and I was wondering whether this is just coincidence, or if there's something in the programming that makes them do this

 

They do spawn in groups more often than not.

Iirc they even plan on doing a "family" system where there are babies that spawn with the mobs and the adults protect them.

 

It's very rare to find a small mob, but they can be easily identified if you look for torches and pitchforks.

Also, even in the Stable build, I think mobs were changed to always hunt in packs some time ago, it made it really tough for gun users.

 

Well, in the near you future they are adding a family system to the game as @Marads said above, but they do currently spawn in pairs.