# Can bees tell the time?

For the past two weeks, I've been sitting on my chair next to a window. On the windowpane is a palm tree plant. At precisely 6 PM over the past two weeks, I have noticed a bee attempting to fly into the window to land on the plant. It obviously cannot fly through the clear glass and soon flies away.

It seems very calculated by the bee to appear outside my window at precisely 6PM, everyday. I wonder if it can tell the time, somehow? It might be sticking to some kind of regime?

Is there a scientific explanation?

## Answers and Replies

anorlunda
Staff Emeritus
I always try to bee on time.

My guess is that it is the angle of the sun. At just the right angle, the bee sees the flower but not the glass.

A good test of that would be to time the bee's arrival time for a month. If the arrival time relative to sunset time is about the same, angle of the sun is a good hypothesis.

berkeman
sophiecentaur
Gold Member
At precisely 6 PM over the past two weeks, I have noticed a bee attempting to fly into the window to land on the plant.
Is there any way you can play yourself along the bee's flight path? There may be a strategic reflection at that particular time that she is following, rather than the plant. It could be navigating somewhere entirely different and then gets deflected by an alternative image of the Sun.
That bee could easily be one of her sisters (as in the penguin joke). There could be a whole stream of bees visiting a particular food source and it could just be 'A' bee happens to be there at the appropriate time and hits your window. You perhaps just didn't see the rest of them.

sophiecentaur
Gold Member
so why not tell time, too?
When trying to 'explain' animal and even human behaviour, it's useful to bear in mind that behaviour develops in response to success or failure in survival. Would there be any advantage in being able to tell the time accurately? There would be if there were specific times when food was available or if it suited navigation. I think that it is much more likely that something repeats itself at the same time every day and the particular bee that happens to be flying past at the time, responds to that and in this case, flies into the window.

A penguin goes into a bar and says to the barman "Have you seen my brother today?"
The barman replies. "Not sure - what does he look like?"

Which bee was involved in this observation?

marcusl
Gold Member
A bee might be the
I think that it is much more likely that something repeats itself at the same time every day and the particular bee that happens to be flying past at the time, responds to that ...
That counts as telling time, in my book. Not much different from noticing when a shadow lies in a certain direction, or when the moon had a certain look, which are how mankind told time for millennia.

sophiecentaur
Gold Member
A bee might be the

That counts as telling time, in my book. Not much different from noticing when a shadow lies in a certain direction, or when the moon had a certain look, which are how mankind told time for millennia.
Is getting out of bed when the sun shines in your eyes 'telling the time'? If so, then we need look no further and say bees can tell the time.

marcusl
Gold Member
The question is whether a bee showing up at a window at 6 pm each day constitutes telling time, and we've established that you believe "no." I'm ready to move on.

jim mcnamara
Mentor
Yes - simply because some species of flowers open at species specific times during the 24 hour period.
Example: Nyctaginaceae family -> Mirablilis spp. "four o'clock". PS: they do not "do" daylight savings time.

Why is this behavior adaptive? If you are the first bee to get into a brand new, just opened flower you have an excellent chance to find a good nectar reward.
Sphinx moths love Mirabilis, too.

See:

There is an older video, a NOVA program on animals keyed into sun, sun angle, and day/night cycles. - back in the 1990's.

Basically, the experimenter had a clock on an outdoor table. Every day at 3pm he uncovered a petri dish with sugar water. The bees soon learned and started showing up within minutes of 3pm. One day he removed the pertri dish completely.

The bees showed up at 3pm anyway.

Some of the answers above are not all that helpful. Google for 'circadian rhythms' for other kinds of examples involving humans

BillTre and berkeman
berkeman
Mentor
A good test of that would be to time the bee's arrival time for a month. If the arrival time relative to sunset time is about the same, angle of the sun is a good hypothesis.
Or see if it still happens on a cloudy day...

When I was house sitting some years ago from the kitchen I could see the veranda of the house next door. The cat that belonged next door would turn up at 5:30 just a few minutes before the owner, every day. Daylight saving came along and one would've expected the cat to be an hour out, but no, it turned up just a few minutes before the owner as usual.

We speculated (not allowed I know), that the cat knew the sound of the owner's car or perhaps some other environmental cue tipped the cat off.

Cheers

berkeman
Mentor
Did they have a grandfather clock with chimes? But since only bees apparently can count...

anorlunda
Staff Emeritus
Pardon my joke. I can't resist.

These bees showed up at the same place every Saturday night.

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BillTre
Gold Member
Being "aware" of the time of day may involve to circadian rhythms.
Circadian rhythms are present in all animals (that I know of) as well as plants and at least some single celled organisms.
Awareness of time of day would be adaptive for almost any organism, since some variable in most environments will be important to an organism and will reward those that can take advantage of it.

Another possibility for bees (honey bees in this case) telling time in a different manner make be how they make use of the information in the bee dance which indicates direction and distance. The insect make use the distance information as a time of flight. This is strictly a conjecture on my part, since I don't know how the bees make use of the distance information or if any on else does.

There are also other clues to time of day and location of the sun that some insects (and other organisms) can make use of such as polarization of the light in the sky and the direction of polarization (some organisms can detect polarized light visually). It is my understanding that this can work even of the sky is overcast.
it also has photographic effects when using polarized filters.

jim mcnamara
Mentor
Bees see into ultraviolet their visible spectrum response is 300nm to ~600nm. They cannot perceive red, but can see part of the UV range. Plants have evolved to provide pigments in petals that provide landing patterns for butterflies and bees. Humans cannot see them. This video displays
First - how humans see the flower
Second - how butterflies see the flower
Third - how bees see the flower
This series is presented for several different species:

As well, this means bees can see the sun disk on cloudy days better than humans do because of polarization. I think @Andy Resnick may have some good resources to help.

https://phys.org/news/2014-01-bees-fantastic.html

Ken Dredge