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Why does catnip make cats go crazy? - Jaap de Roode - Video học tiếng Anh
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Why does catnip make cats go crazy? - Jaap de Roode
Why does catnip make cats go crazy? - Jaap de Roode
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자막 (74)
0:06
Of the many bewildering behaviors cats display,
0:10
one of the strangest is their obsession with a specific species of plant.
0:15
After just one whiff, even the most stoic cat
0:19
can start pawing, drooling, biting, and wriggling
0:23
in a state of pure feline euphoria.
0:27
So, why do cats go crazy for catnip?
0:31
This is the question cat behavior expert Masao Miyazaki
0:36
and chemist Toshio Nishikawa set out to answer in 2013.
0:41
Along with their research teams from Iwate and Nagoya University,
0:46
they began by studying silvervine—
0:48
a plant that sparks a similar response to catnip.
0:52
First, the researchers painstakingly extracted chemical compounds
0:56
from the plant
0:58
and dribbled various combinations of them onto filter papers.
1:02
Then they brought in some cats and studied which compounds they were drawn to.
1:07
Overwhelmingly, their feline testers pounced on the papers
1:11
containing nepetalactol.
1:13
And when Miyazaki and his student Reiko Uenoyama
1:17
ran blood tests on the cats who’d interacted with nepetalactol,
1:21
they found their systems were flooded with endorphins.
1:25
These hormones block pain signals, relieve stress,
1:28
and generally create a happy, calming effect.
1:31
And catnip triggers the same endorphin rush
1:34
with a similar chemical called nepetalactone,
1:38
and it’s this flood of happy hormones that gives catnip and silvervine
1:43
their signature drug-like response.
1:47
These compounds don't just trigger this effect in small cats.
1:50
When the researchers brought nepetalactol-treated filter papers
1:54
to a few zoos,
1:55
leopards, lynxes, and jaguars all dove face first into the compound.
2:01
This was big news.
2:03
If all these different cat species reacted to nepetalactol in the same way,
2:08
the response was very likely a shared evolutionary trait—
2:12
potentially something important to cat survival
2:14
that stretched back millions of years.
2:18
When the silvervine researchers presented their work at a conference,
2:21
one evolutionary biologist raised a compelling theory.
2:25
In chemical terms,
2:26
both nepetalactol and nepetalactone are classified as an iridoid—
2:32
a type of natural compound known to contain insect-repelling properties.
2:37
So perhaps cats rubbing their faces in silvervine and catnip
2:41
were applying an ancient form of bug spray.
2:45
To test this, researchers set up cages of mosquitoes
2:48
that cats could stick their heads into.
2:50
And sure enough, the cats that had been treated with nepetalactol
2:54
got fewer mosquito bites than the cats in the control group.
2:58
The same effect was true for the scientists who’d volunteered their arms
3:02
in solidarity with their feline subjects.
3:05
These mosquito-repelling properties are currently our best explanation
3:10
for why cats love silvervine and catnip.
3:13
But researchers still had one more question:
3:16
in their state of euphoria,
3:18
cats tend to vigorously bite, lick, and rub against these plants.
3:23
But do cats really need to go this crazy to get their bug repelling effects?
3:29
To investigate rubbing, they provided cats with filter papers
3:32
treated with microscopic amounts of nepetalactol.
3:36
And sure enough, even these tiny doses made the papers irresistible,
3:41
suggesting that microscopic amounts of bug repellent can be transferred
3:45
by rubbing alone.
3:46
As for biting and licking, the researchers found that when cats damage the plant,
3:51
the leaves actually produce more mosquito-repellent chemicals.
3:56
So your cat isn’t just ripping open their bags of catnip to be annoying,
4:00
their evolutionary instincts are just trying to get even more
4:04
of that bug protection.
4:07
Cats are far from the only animal to use natural plants for purposes like this.
4:12
Apes swallow scratchy and hairy leaves to dislodge parasites from their guts.
4:17
Sheep munch on tannin-rich plants to kill intestinal worms,
4:21
and monarch butterflies use toxic milkweed
4:25
to kill parasites that normally impair their flight.
4:28
Just like cats’ ability to find mosquito repellent,
4:32
these behaviors can help humans identify useful plants and ingredients
4:36
in the natural world.
4:37
So, the next time you see your feline friend on catnip binge,
4:41
don’t worry— it’s only medicinal.
