-What's happening around the site is really important to bees. So bees can nest within this site, but they might forage up to a kilometer or two outside of the site. And what is really striking is the level of agriculture has gone up by about 30 percent. So I will show you an old map. This is what this area used to look like in the 1920s and 30s, and all the light green bits that you see are meadow land and grasslands, with a little bit of agriculture, which is the brown bits. But if you look out of the window now, the entire countryside is turned into quite intensive agriculture and farming.

Deep's research is being repeated around 23 other sites in the U.K., and they all show the same thing. Although this landscape may look greener, it's what ecologiests call, a green desert. Over the years, plants that bees do feed on have been replaced by vast expanses of plants that they can't feed on.

-It is quite c*, because you look at green, you look at p* plants you can see there. You think that must be really good for bees and pollinators.

-The logical conclusion would be then that we need to rethink our entire system of modern agriculture, the way we grow things.

-I think it's just a slight shift in perhaps thinking of more wildlife-friendly farming methods, not saying agriculture is bad. It's just ways. There are ways to improve agriculture in a way that it might be more useful to the biodiversity, might be more friendly.

So you won't be surprised to hear that scientists aren't simply looking at why bees are dying. They are also trying to work out what we can do about it.