Excavation Has Gone Nuclear: 24 g Shifted

Almost 24 g of material, excavated by ants. © Eugene Brennan

The ants have been excavating tunnels under the floor of my utility room for the last few years. This occurs during the summer. It would be a lot of hassle blocking up the holes because the tunnel entrance is behind a door jamb. Anyway, sorting this problem is low down on my ever-growing-longer list of chores. There was a huge amount of activity overnight, taking advantage of the dry weather. Construction has carried on into the daylight hours, which is unusual. Are there ant "weather forecasters" that give the go ahead for mass mobilisation of construction workers like what happened on D-Day? I weighed the material excavated in the last couple of days on my drug dealer scales (or so it was called by members of an electronic forum I'm a member of. Disclaimer: I'm not a drug dealer) and it's almost 24 g (one ounce = 28.35 g) . According to a BBC article, an ant weighs 1 to 5 mg. However they can also lift 20 to 50 times their own weight, depending on species. The material they were excavating under my floor was small soil/sand particles probably equalling the weight of an ant, so I guess lots of ant-hours of backwards and forward movement was required, rather than Herculean lifting skills.

Sand and  soil excavated by ants. © Eugene Brennan

Structural Colour and Iridescence

A green bottle. © Eugene Brennan

A species of green bottle I think. Sorry quality not the best. Normally the way colour works is that if an object is illuminated by light, pigment in the surface absorbs some wavelengths and reflects others. The Sun mostly produces broad spectrum white light, so a red rose looks red because it absorbs all the colours of the rainbow in white light and only reflects red. Some animals, insects and plants have evolved so they can produce structural colour on their body's surface which doesn't rely on pigments. Instead, the topography of the surface is such that tiny elements like ridges or other structures, having dimensions comparable to the wavelength of light, produce iridescent colours. Iridescence is a phenomenon that makes soap bubbles, oil spilled on a wet road, opals and the underside of CDs look colourful. It's caused by wave interference where waves of light combine and the peaks and troughs add or subtract from each other to reinforce certain wavelengths, making colours emerge from white light. Beetles, blue and green bottles, some butterflies and starlings are examples of animals that use iridescence. The theory is that it confuses predators or is used for communication.