Tilemap has gap between tiles, how do I get rid if it.

I’ve created a script that creates a bunch of tiles, but all of the tiles have a gap between them, what is a good way to get rid of the gaps.

Here’s a picture:

here’s the code used to generate the tiles

using UnityEngine;
using System.Collections;

public class TileLoader : MonoBehaviour{
	public GameObject prefabTile;
	public int TileWidth = 16;
	public int TileHeight = 16;
	public int size = 3;

	// Use this for initialization
	void Start () {
	// Update is called once per frame
	void Update () {
	void loadTile()
		for(int i=0; i < TileWidth; i++)
			for(int j=0; j<TileHeight;j++)
			GameObject tile = Instantiate(prefabTile, new Vector3(i*size,0,j*size),Quaternion.Euler(0,0,0)) as GameObject;
			tile.transform.parent = transform;

Come now. You have a variable called size which is set to 3. This is used to separate the blocks. Look up the size of the tile. My suspicion is that it’s smaller than 3 units.