RaycastHit2D should be child object but is parent

Hi! I have a child object that is rendered on top of its parent object. They both have trigger colliders.

I'm trying to use raycast to detect when I click the child object, but the RaycastHit2D returned has the collider of the parent object and not the child.

 private RaycastHit2D hit;

 void Update()
 {
 
     if (Input.GetMouseButtonUp(0))
     {
         Vector2 worldPoint = Camera.main.ScreenToWorldPoint(Input.mousePosition);
         hit = Physics2D.Raycast (worldPoint, Vector2.zero);
         Debug.Log(hit.collider + " using raycast");
         //Debug.Log(hit.transform.gameObject.name + " using raycast");
         //Debug.Log(hit.collider.transform.name + " using raycast");
         //Debug.Log(hit.collider.name + " using raycast");
         // All commented outs above give the same result as the one not commented out
     }
 }

However, using the following method in a script on the child object correctly returns the child object.

 void OnMouseUpAsButton()
 {
     Debug.Log (gameObject.name + " from OnMouseUpAsButton");
 }

So to be clear, when I run the game and click the child object, the Debug.Logs print:

"childObject from OnMouseUpAsButton"

"parentObject using raycast"