Wasps return to their nest at night, so it’s best to spray the nest in the evening when they’re less active. If you’re allergic to wasp stings, don’t try to remove the nest yourself. Call a professional for help. You can also spray wasps’ nests in the morning, but be sure to do it before the wasps become active. Be careful when spraying wasps’ nests, as some wasps may become aggressive. It is important to note that not all chemicals and methods will work for every infestation. Contact Birch Fumigators today for a free consultation to get tailored advice for your situation.