Field Notes Journal Entry
An Encounter with Tipsy Tree Bumblebees
Observations of apparently intoxicated tree bumblebees (Bombus hypnorum) during a UK heatwave, and the curious ecology of fermented nectar
There are some things one expects to see during a British heatwave.
Wilting plants.
Garden chairs dragged optimistically into the sun.
People insisting “it’s too hot” after spending eleven months complaining about rain.
What I had not expected to see was a drunk bumblebee staggering across the patio.
We had been sitting outside enjoying the unusual warmth and evening sunshine when we noticed her: a female Bombus hypnorum tottering uncertainly across the paving stones. She seemed entirely unable to decide where she was going. Every few moments she would stop, change direction, clamber awkwardly over a tiny weed growing between the slabs, then continue onward with the determined but deeply unconvincing air of somebody leaving a pub at closing time insisting they were “absolutely fine.”
At first glance, it was genuinely worrying. A bee on the ground is often not a good sign.
But this one looked … intact.
- No twitching
- No frantic spasms
- No obvious injury
Just gloriously, unmistakably, tipsy.
Then, later that evening, after the worst of the day’s heat had faded, I went out to water the plants and found another female tree bumblebee stumbling erratically across the lawn in much the same fashion.
Which raised an obvious question:
Can bees actually get drunk?
As it turns out — yes, they can.
Nectar is basically sugar water, and in hot weather yeasts can begin fermenting sugars into alcohol. Bees may also encounter ethanol from overripe fruit, sap runs, or aphid honeydew. Under the right conditions, flowers and sugary plant residues can become tiny natural fermentation vessels.
And during a UK heatwave, with warm air lingering well into the evening, the conditions are probably rather favourable for it.
The result, apparently, is exactly what we witnessed:
- Clumsy walking
- Poor coordination
- Hesitant or erratic flight
- Long pauses
- Behaviour best described as “bee after two glasses of wine.
The tree bumblebee itself feels oddly appropriate for this sort of encounter. Bombus hypnorum is a comparatively recent arrival in the UK, first recorded here in 2001, and has since become a familiar garden species. They are energetic, adaptable, highly visible bees — the sort that investigate every flowering corner of a garden with tremendous enthusiasm.
Including, it seems, the accidentally fermented ones.
There was also something faintly comforting about the whole scene. The behaviour looked absurdly familiar in human terms: the uncertain navigation, the repeated attempts to climb things, the vague sense that important decisions were being made very badly.
And yet beneath the comedy sits a rather beautiful ecological detail.
Flowers are not sterile objects. They are tiny living micro-worlds inhabited by yeasts and bacteria, shaped by weather, temperature, sugar chemistry, and the visits of countless insects. The relationship between flowering plants and pollinators is ancient and immensely complex — and somewhere within it exists the possibility that, every now and then, a bumblebee slightly overdoes the fermented nectar.
Which is a sentence I never expected to write.
Still, the two bees eventually recovered enough to continue on their way, albeit with somewhat questionable dignity intact.
I suspect the weeds between the patio slabs may still be talking about it.