I live on a ground floor in a tropical country - this is my reality every morning I open the front door.
When you live on a ground floor you have to really cover up all nooks and crannies and one major area is the gap at the bottom of the floor. So, we use these sticky door gap covers (like this one) that also act as traps for tiny bugs that could fit through it. Well those tiny trapped bugs attract predators and while they are too big to get in there they can sense prey and chill in front of your door which is a sure way to get spooked once you open the door in the morning :O