When I looked at the poster showing an alligator in Crawl (Blu-ray release 2019-10-15), I got scared because of the experience I had with the Thai crocodile-in-The Pool (2018) movie, which is a trash movie offering only stupidity and bad taste instead of scariness.  Fortunately this is a much, much better and enjoyable movie with very good visuals for its budget.  This is an effective thriller showing a daughter and her father trying to escape from alligator(s) inside their house.  The house setting allows for scenes not seen in other alligator movies.  Other than really questionable assumptions about the nature of alligator(s) and how to apply these rules to escape from being eaten, I have no complaint.