How do I stop the word "categories" from printing

I have created a custom products page that lists the subcategories of the page. I can't figure out how to hide or delete the word "categories" that keeps displaying above the category list. I am using the function: <?php wp_list_categories('child_of=3&orderby=name'); ?>

Here is the dev page: http://dfg.detroitfuturelab.org/products