How to make subcategory not show ?

[GTBrealestate]

I need some help with getting a category or rather a sub-category to NOT SHOW in my Recent Listings sidebar.
http://www.greatertampabayrealestate...-family-homes/

Ok, I have put Open House under the Category of Single-Family-Homes as a sub category called Open House.

When I post a New Open House event, we want it to show on the blog, and in the sidebar as Blog Post and NOT a Listing Event.

Here is the code for showing/display of the Single-Family-Homes (Listings) how do I code this to exclude the
subcategory which is 166 ?

I know how to include it so it shows as a Blog post....in this example, I have omitted showing it twice on the same page until I can resolve the issue.

<?php $recent = new WP_Query("cat=6&showposts=10");

Thanks