Post on 03-Jan-2017
The last word–
POTTY ANTSOn our patio we have strawberry
plants in pots. For the past two years
we have noticed that large numbers
of ants systematically bring small bits
of dirt, gravel and woodchips, and
pile them around the bases of the
plants and their runners (see Photo).
It seems they are cultivating the
plants. When the strawberries are
grown, however, the ants do not
always eat them, but sometimes bury
them. The plants seem to thrive –
what is going on?
The ants are not cultivating the plants; they are using the roots as a structure for their nest. It is easier to run up and down a root than to clamber over soil particles. As the ants excavate their nest, they carry the soil to the surface and extend their nest upwards, covering the plant. This is the beginning of an anthill.
The plants thrive because their roots have a good air and water
supply, are kept clean and are supplied with abundant waste products from the nest. It is a form of symbiosis. It can also help gardeners – on my lawn, where the ants colonise dandelion plants, they loosen the soil around the roots making it quite easy for me to pull up the weeds.Richard Lucas
Hawley, Hampshire, UK
No ants, as far as I am aware, are known to cultivate green plants in the way described. I suspect that what is happening is that the ants are incorporating the stems and runners of the strawberry plants into their nest excavations, perhaps using them as supports for galleries. You do see this on anthills where plants that have colonised the mounds become partially buried by the ants’ activities.Jeff Ollerton
Landscape and Biodiversity
Research Group,
University of Northampton, UK
TEETHING TROUBLEWhy does eating cooked spinach
make my teeth feel funny?
Spinach contains a large amount of oxalate crystals – mineral salts of oxalic acid. When spinach is cooked, especially canned, heat-processed spinach, some of the spinach cell wall structure is damaged and oxalate crystals leak out. It is this oxalate that gives your teeth and mouth that fuzzy coated feeling.
Spinach is also rich in calcium, and
Last Words past and present, plus a full list of unanswered questions, are available on New Scientist’s website at www.newscientist.com
“The ants are not cultivating the
plants, they are using the roots
as a structure for their nests”
THIS WEEK’S QUESTIONSThe three questions below were all
asked by listeners of BBC Radio 5 Live
when the new Last Word book Why Don’t Penguins’ Feet Freeze? (see
below) was featured on the Anita
Anand show – Ed
Night light flight
If moths are nocturnal, why are they so keen to fly towards light?
No wrinkles
How do they get the smooth, round chocolate coating on confectionery like Maltesers and Whoppers?
Coconut cruise
How long would it take a coconut to float from the Caribbean to the west coast of Scotland?
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WHY DON’T PENGUINS’ FEET FREEZE?The latest collection from The Last Word, answering some of the world’s most baffl ing questions
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calcium oxalate crystals deposit on the teeth, coating them with plaque. Not much oxalate is released when eating fresh spinach because you chew it for only a short time.
People who have problems with kidney function should avoid spinach and other foods that contain oxalate, because of the increased risk of producing oxalate stones in their kidneys.Johan Uys
Bellville, South Africa
Spinach contains oxalic acid, which combines with the calcium in your saliva to produce the furry feeling on your teeth. Rhubarb, chard and beetroot leaves will all do the same.Nigel Jones
Littlehampton, West Sussex, UK
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