I have a half-inch gap between the foundation of my garage and my house. We're having some trouble with spiders, and have seen some mouse-droppings so I'm trying to fill any cracks and crevices that may be inviting to these pests.
What should I use to fill this? Is cement a good option or do I need something that will allow this space to expand/contract with the change in seasons? If I need something less rigid then what should I use?
Here's a photo of the gap.