Bumblebee nest. Photo: peacebeefarm.blogspot.com
Question: I have a bumblebee nest in the ground at the entrance to my house. How can I chase them away or outright exterminate them?
Answer: Before answering, I feel I have to point out that bumblebees (Bombus spp.), large hairy bees generally striped black and yellow, are beneficial to our gardens, being excellent pollinators and, moreover, are not aggressive. They very rarely sting. So, normally it’s best to just ignore them. If you discover a nest while gardening (usually it’s underground, but can also be found in a structure of some sort, like a bird box, a hole in a wall or a hollow tree), just avoid it. Unless you actually attack the nest or try to dig it up, they’re very unlikely to react. You could put a warning flag in front of the exit hole or, if there are children playing in the area, surround it with a fence: something that would tell all the humans in the area there’s a bumblebee nest to be avoided. And that way, both humans and bees will be happy.
But sometimes, as in your case, the nest is just in the wrong place and the risk of an unfortunate encounter with humans is very high. And I don’t think you, your family, or visitors should risk being stung, especially since some people may be allergic to bumblebee stings. So, there are situations where you just have to get rid of nesting bumblebees.
However, you cannot simply “chase them away”. This isn’t a garden of flowers you could maybe shoo the bees away from. It’s their home and the nest may host a colony of more than 100 bumblebees. Plus, the colony’s only queen will be in residence and bumblebees won’t abandon their queen. You could never “encourage” an already established colony to take up residence elsewhere: they’d rather die than move!
When a bumblebee nest is clearly in the wrong place, the easiest thing to do is to eliminate it. Kill ’em all. Sorry if that upsets the faint-hearted, but in my opinion, that’s the logical thing to do.
You’ll have no trouble finding wasp spray in garden centers or hardware stores. True enough, wasp insecticide was designed to control wasp nests, but it’s effective against bumblebees as well. At night, direct the nozzle into the nest’s exit hole and push on the button to fill it with spray. Do wear gloves and long sleeves, just in case, but there is little danger. Bumblebees can’t fly in the dark. If ever a few manage to get out of the nest, they’ll be more confused than angry and they’ be crawling, not flying.
Sometimes you need to apply a second treatment the following evening to finish the job.
If that’s too much for you, bring in an exterminator.
But Couldn’t You Move the Nest?
Actually, that’s probably crueler than just spraying the nest and getting things done fast.
Trying to dig up and move a bumblebee nest is a very delicate operation and you usually end up seriously damaging it. Also, the stress to the colony of the disruption is such that it rarely recovers from such a move. They’ll all die anyway; it will just take longer. And if you really wanted bumblebees to sting you, that would be the way.
The exception is when the nest is located in an object that you can easily move (a flowerpot, a birdhouse, etc.). Even then, don’t move it more than 6 feet (2 m) or so from its original location; otherwise the bumblebees will become disoriented when they take off on a pollinating mission and won’t be able to find their way back home.
Move the nest at night, wearing protective clothing just in case. Ideally, you’d have the help of a friend to hold a red light flashlight* to light your way.
*Bumblebees can’t see in red light, but you can.
Or Let Ma Nature Do It!
So much for what to do in the summer, when bumblebees are most active. However, I received this message on September 21st, and that means there is another possible solution.
I’d like to suggest you wait a few weeks, maybe even just a few days. Because the problem is about to correct itself. That’s because bumblebee colonies are annual structures, lived in once, never to serve again. And the end is nigh!
Each fall, the entire colony dies with the onset of cold weather. So, by the end of September, the season is already almost over. In fact, the bumblebees are probably already less active and may, in fact, already be dying.
Next season’s nests will be founded come spring by new queens. They already left the old nest a while back, mated and, now filled with fertile eggs, are hibernating somewhere underground. In spring, the new queens will again take flight and search for an ideal new home. They’re not interested in old nests, as they likely harbor predators and diseases. They want a fresh start.
Maybe you actually only noticed the nest a day or two ago, but if so, look again. This is so close to the end of the season that there may already no longer be any bees entering and leaving the nest. And why spray a dead colony?!
If the bumblebees are still active and you simply can’t wait, by all means, use insecticide as mentioned above to hasten the end of the colony. It’s already living its last days anyway.