Walking particles appear under Iron Golem's feet even when they have no AI, unlike many mobs.

I summoned an Iron Golem without Ai using /summon minecraft:iron_golem ~ ~ ~

{NoAI:1}

and noticed that it had walking particles of the dirt it was on even though it was not moving. I tested out other mobs such as a villager and they did not have walking particles under them.
Is this a bug or intentional?