Fawn in the Rain

I checked my camera trap today and found an ant colony had taken up residence in its nooks and crannies. They were only on the outside but clearly messed up a large number of images as they moved across the camera lens during the last 3 weeks. I have heard of this happening but it was a first for me. I'm not sure how to prevent it either. Fortunately they had not messed up the best video on the card.