Want to remove that nest of yellow jackets? There's an official fact sheet that was developed by environmental experts in the Department of Agriculture of Canada's Prince Edward Island. Their advice? Don't do it yourself. Call a professional "Nest removal can be dangerous," reads their official warning, "and extreme caution must be used because of the danger of attack by a large group of wasps."
If you really want to brave the danger, they advise, don't do it in late summer. That's when yellow jacket colonies are the biggest - and because they're all packed together into the same tiny nest, the yellow jackets are also at their most aggressive. So it's late summer when they're most likely to attack in a massive swarm if their nest is disturbed.
Remember that yellow jackets are attracted to scents, including hair spray, colognes, and aftershave. And the Department of Agriculture also advises that if you do approach a nest, be smart - and wear protective clothing. They suggest approaching the nest just before dark, (though one California newspaper recommends removing the nest at night). This approach ensures the worker insects will all be in the hive - and they'll be less active than they are during the day. But don't shine a light directly on the nest, since this agitates the yellow jackets, and makes them more active.
While there's many way to build simple yellow jacket traps, this will only address some of the insects - and not their entire colony. Having said that, it's much easier to dispose of a nest that's hanging in a tree. (Quickly cover the nest with a bag - making sure to block the nest's exit hole - and then take care to dispose of it safely). When the nest is underground, it's more difficult to contain. And again, the Department of Agriculture warns that its disposal is "best left to a professional pest control operator."
One of their most disturbing stories involves a nest of yellow jackets that was built into a wall. Plugging its exit hole seemed like a good idea - but it led to unintended consequences. The yellow jacket mouths are actually very strong, and new exits soon appeared. "If their normal exit from the nest is plugged, they may chew through the wall and emerge inside the building!"
One of the most common remedies it to pour gasoline down the hole - but unfortunately, it's illegal. (Not to mention that it's also extremely dangerous, according to the California newspaper, and also bad for the environment). But whatever you do, keep in mind that yellow jackets are a venomous, predatory insect, and take their danger seriously If you smash one of them, it will give off a pheromone which signals to the rest of the swarm to attack! So don't try to deal with a yellow jacket nest by simply swatting them away.
You'll never swat away all of them. And it only makes them madder!