54 | New Scientist | 1 February 2020
Fish dish
Cats love to eat fish yet seem to hate
getting wet. How would they catch
a fish, never mind get to eat one,
before they were domesticated?Jane Monroe
Arcata, California, US
Of the extant wildcats, the fishing
cat, Prionailurus viverrinus, and
the flat-headed cat, Prionailurus
planiceps, are experienced fishers.
The domestic cat’s ancestors
were desert dwellers with little
opportunity to dine on fish.
Domestic cats, however, are great
opportunists and are willing
to try anything at least once,
if my cat is any indication.
Fish has a strong and distinctive
odour, so it seems reasonable to
assume that cats are attracted by
its smell and then decide: hey, this
stuff tastes pretty good.
As demonstrated by countless
videos online, cats won’t hesitate
to steal food from other animals,
including humans. If small
wildcats and their domestic
cousins develop a taste for
seafood, they could obtain it
through thievery. No wetting
of paws is necessary.Simon Dales
Oxford, UK
Cats are much like people in
that they don’t want to get wet
unnecessarily – but lunch is a
different kettle of fish. Turkish
Van cats love swimming and will
join you in the bath. Even British
moggies quite like water, especially
for cooling in the summer.Alex Marr
Lockerbie, Dumfries
and Galloway, UK
When I lived in Kiribati, a small
archipelago in the equatorial
Pacific, my cats used to bring me
gifts of live eels they had caught
on the reef. They would also follow
me into the shallow water on the
reef when I went out net fishing
at night, so they had obviously
overcome their dislike of water.
Maybe the fact that the water
was warm helped them to adapt.Wendy Roberts
Buckfastleigh, Devon, UK
When we moved house, our
Siamese cat presented us with a
25-centimetre golden orfe every
morning for nine days. She had no
qualms emptying our neighbour’s
pond of his precious fish.Mary Sinclair
Martletwy, Pembrokeshire, UK
When I was a teenager, we had
a large black cat that used to fish
from a stone at the edge of the
Pembroke river. He would perch
there patiently for hours, one paw
ready. When a fish appeared, he
would spear it with his claws. It
amazed us that he managed to
catch eels as well as trout.
He never shared his spoils and
was the only one of the many cats
we had that we ever saw fishing.Katherine Hevezi
London, UK
Cats are fascinated by water,
even if they are reluctant to
get into it. My cat would evenleave a succulent turkey leg
to watch a bath being run.
She returned to the turkey
once the water had gone.David Critchard
Exeter, Devon, UK
I would say that cats like meat –
the type is largely irrelevant.
A friend and I once experimented
with some domestic cats, both
pampered house cats and feral
cats from the farms on my friend’s
estate. The meat they liked most
was offal: raw liver or kidney above
all, but spleen and brains too.
Fish was one of the cheapest
proteins available to people in
Victorian days, so perhaps it
came to be seen as cats’ favoured
protein, but I have found they
really prefer energy and
nutrition-rich offal.Mind fuel
How many calories go on
running the brain? Could I burn
more calories by trying to do lots
of difficult mental arithmetic or
solving the New Scientist cryptic
crossword? Could I actually think
myself thinner?Jason Arunn Murugesu
London, UK
Although the brain only makes
up about 2 per cent of total body
weight, it accounts for some 20 per
cent of the body’s resting energy
use. Yet compared with electrical
devices, it is quite efficient. For
someone with a resting metabolic
rate of 1300 kilocalories, the brain
consumes around 260 kilocalories
a day. This is about 12 watts, which
is about a fifth of what it takes to
run a standard lightbulb.
The amount of energy used by
the brain remains much the same
whether you are resting or active
in some way. Overall, cognitive
effort has a less than 5 per cent
effect on brain activity, so it is
unlikely that you will be to be
able to think yourself thinner.Helen Thomson
London, UK
Although extra mental effort can
consume slightly more calories,
the more skilled you become at
something, the more efficient
the brain can become. So, in the
end, you might actually expend
less energy doing it.You might not lose weight, but a
study published in 2017 found that
“brain-training” activities that test
memory and reasoning helped
ward off dementia. So it is still
worth trying to solve the New
Scientist cryptic crossword – Ed ❚This week’s new questions
Nuts for apples A squirrel surprised us this autumn by
picking apples from a tree and placing one each in hanging
baskets around our garden, as well as putting two on top of
the fence. Is this unusual behaviour for a squirrel? Allan Smith,
London, UKAtomic space A hydrogen atom consists of a proton with
an electron whizzing around it. What is in the space between
them, and what happens to the space when the atom loses its
electron? Robert P. Bodnaryk (by email, no address supplied)Want to send us a question or answer?
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ROS^ CROSLAND/ALAMYSTOCK^ PHOTOIs it normal for squirrels
to spread apples around
a garden?