Implementing critter AI, so far got the prototype working. AI is done using Behavior Trees, only a few lines of code:

RepeatBehavior.from(
    SequenceBehavior.from([
        PickWanderPathBehavior.fromJSON({ radius: 5, anchor, distance, axis }),
        StartAnimationBehavior.fromJSON({ name: wanderAnimation, repeatCount: Number.POSITIVE_INFINITY }),
        ParallelBehavior.from([
                new CheckPathEndBehavior(),
                WaitForEventBehavior.fromJSON({ event: PathFollowerEventType.EndReached })
            ],
            ParallelBehaviorPolicy.RequireOne,
            ParallelBehaviorPolicy.RequireAll
        ),
        StopAnimationBehavior.fromJSON({ name: wanderAnimation }),
        StartAnimationBehavior.fromJSON({ name: idleAnimation, repeatCount: Number.POSITIVE_INFINITY }),
        RandomDelayBehavior.from(2, 5),
        StopAnimationBehavior.fromJSON({ name: idleAnimation }),
    ])
);

The PickWanderPathBehavior creates a new path to follow around the anchor point within a given radius, in this case 5. Here’s what this loos like in action