Make it so if the follower is a certain distance away, teleport it back to its spawn?

This is the code that determines its spawnpoint.

using UnityEngine;
using System.Collections;

public class MainLevel : MonoBehaviour {

	public GameObject NcolGrass;
	public GameObject ColWood;
	public GameObject Player;
	public GameObject HumanFollower;

	public Color NcolGrassColor;
	public Color ColWoodColor;
	public Color PlayerSpawnColor;
	public Color HumanFollowerSpawnColor;

	private Color[] TileColor;

	private int LevelWidth;
	private int LevelHeight;

	public Texture2D LevelTexture;

	void Start () {
		LevelWidth = LevelTexture.width;
		LevelHeight = LevelTexture.height;
		LoadLevel ();
	}

	void Update () {

	}
	void LoadLevel () {
		TileColor = new Color [LevelWidth * LevelHeight];
		TileColor = LevelTexture.GetPixels ();

		for (int y = 0; y < LevelHeight; y++)
		{
			for (int x = 0; x < LevelWidth; x++)
			{
				if (TileColor [x + y * LevelWidth] == NcolGrassColor)
				{
					Instantiate (NcolGrass, new Vector2 (x, y), Quaternion.identity);
				}
				if (TileColor [x + y * LevelWidth] == ColWoodColor)
				{
					Instantiate (ColWood, new Vector2 (x, y), Quaternion.identity);
				}
				if (TileColor [x + y * LevelWidth] == PlayerSpawnColor)
				{
					Instantiate (NcolGrass, new Vector2 (x, y),Quaternion.identity);
					Vector2 PlayerPos = new Vector3 (x, y);
					Player.transform.position = PlayerPos;
				}
				if (TileColor [x + y * LevelWidth] == HumanFollowerSpawnColor)
				{
					Instantiate (NcolGrass, new Vector2 (x, y),Quaternion.identity);
					Vector2 HumanFollowerPos = new Vector3 (x, y);
					HumanFollower.transform.position = HumanFollowerPos;
				}
			}
		}
	}
}

Vector3.distance may help you …