Destroyed Objects not disapearing

I’ve got a code wich detects collision with my Cat object and then destroys itself.
But the mouse object is not disappearing.

   void onTriggerEnter2D(Collider2D mcol)
    {
        if (gameObject.name.Contains("Clone"))
        {
            if (mcol.name.Equals("CAT"))
            {
               Destroy(this.gameObject);
            }
        }

    }

This:

void onTriggerEnter2D(Collider2D mcol)

should be:

void OnTriggerEnter2D(Collider2D mcol)

Notice the case difference in the method name.

Try using Destroy(gameObject);