Colliding Objects

Hello there, i need to destroy my gameobject when i click that object. The following code is working fine, but i want to destroy the objects with some particular distance. Which means if my object is far i need to go close and click that object.

using UnityEngine;
using System.Collections;

public class Capture : MonoBehaviour 
{
	RaycastHit Weapon_Hit;
	public int Rat, Frog, Snake;

	void Start()
	{
		Rat = 0;
		Frog = 0;
		Snake = 0;
	}

	void Update()
	{
		if (Input.GetButton ("Fire1")) 
		{
			if (Physics.Raycast (Camera.main.ScreenPointToRay (Input.mousePosition), out Weapon_Hit)) 
			{
				if (Weapon_Hit.collider.tag == "Rat") 
				{
					Rat = Rat + 1;
					Debug.Log ("Rat: " + Rat);
					GameObject.Find("Rat_Count_Text").guiText.text = " " + Rat;
					Destroy(Weapon_Hit.transform.gameObject);
				}
				if (Weapon_Hit.collider.tag == "Frog") 
				{
					Frog = Frog + 1;
					Debug.Log ("Frog: " + Frog);
					GameObject.Find("Frog_Count_Text").guiText.text = " " + Frog;
					Destroy(Weapon_Hit.transform.gameObject);
				}
			}
		}
	}
}

-Prasanna

add distance to your physics.racast

  private float dist;
    void Start()
        {
          dist=1000//for example
        }
        if (Physics.Raycast (Camera.main.ScreenPointToRay (Input.mousePosition), out Weapon_Hit,dist))