The bad guy is trying to figure out if there are children hiding in the house. The owner of the house knows where they are and so does the reader but is trying to convince the bad guy that he knows nothing. There conversation is not about the children or their location but about something else. If the children make any noise they will get caught.
The goal of this exercise is to create suspense. You can add to the fear of the children getting caught by coming up with a reason that it’s likely that they will make a sound at any moment. Maybe there is a hungry baby with them who could wake up and start crying any moment. Or one off the kids was out in the rain last night and is has been sneezing. One of them could have a fear of spiders and we see one crawling behind him or her and coming closer and closer, but the child hasn’t noticed it yet.
Note that you are playing with information distribution. In the case of the spider, the reader knows more than the children. During the whole scene the reader knows more than the bad guy.
