Can you spray ammonia in the yard to prevent mosquitoes?

I don't know for a fact that it does but my hunch would be that it does. Ammonia is the active ingredient in what people often call "smelling salt" and when inhaled, it triggers a quite unpleasant reaction in any air breathing animal. I once let my cat smell some smelling salt and she turned and ran the other way.

Also I was spelunking last week and it wasn't until I got into a cave and mosquitos swarmed me that I realized I forgot bug repellant. So, thinking quickly, I grabbed my stick of afterbite from my first aid kit (which contains a high amount of ammonia) and rubbed it on my arms and neck. Suffice to say I didn't smell great, however, I don't have a single bite. So my theory is that yes, ammonia can repel mosquitos.