this is a common american cockroach a
household pest when i normally see a
roach like this outside my lab it's
usually in a full out sprint running
across the floor and diving into a dark
corner
but recently i've been trying to see
roaches in a new way for instance have
you ever seen a roach do this
lift its wings push itself off the
ground and jump into a short burst of
flight
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like anybody i admit that roaches are
kind of gross and i don't want to see
them crawling across the floor in my
house but they're also kind of
fascinating for instance recently i came
across this paper from 2012 which was
the first to describe something called a
leap roach
it's a species of wingless cockroach
from south africa that evolved
grasshopper-like hind legs and a high
flying jump
but in the introduction of this paper
the authors write that no other roach
species are known to be able to jump as
you saw on the first part of this video
other roaches definitely do jump what
that sentence told me is that no one's
taken the time to carefully film observe
and describe the aspect of their
behavior before
so we've been doing a little bit of that
and i want to show you what we found so
far
here are three of the most common pest
species of roach all jumping
on the left is a german cockroach the
middle a smoky brown and then on the
right an american
these sequences were all captured at 6
000 frames per second and they all show
that a flight starts with a leg powered
jump
i filmed this behavior by putting the
roaches on a platform they couldn't
crawl down off of
but even when their aim was down towards
the ground they would still use their
legs to push off the platform and jump
out and away
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after filming a bunch of these i noticed
one mechanic that i think is unique to
the cockroach jump if you watch the hind
legs they aren't touching the ground
when the roach starts its motion instead
the middle legs initially power the jump
while the back legs are dragged up and
positioned parallel with the middle
all three species that i filmed do this
repositioning of their back legs once
their jump has started
to show how different it is here's a
comparison mantises are the most closely
related group of insects that also jump
here's how a young wingless chinese
mantis does it
notice how it jumps from a standstill
there's no repositioning of the legs no
sequential push of the middle and then
hind legs it's just four legs all
pushing at the same time
side by side the differences in leg
movements seem pretty clear
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up to now all that footage was roach's
jumping right before they flap their
wings into a short burst of flight but
we found some situations in which they
jump without using their wings at all
here's an american roach facing a gap it
can feel the other platform with its
antennae but when it tries to grab a
hold of it with its front legs it's too
far out of reach
if it wants to get to it it has to
either jump or fly
this one jumps demonstrating a full out
leg powered jump without any wing
flapping
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when this one gets across the gat watch
as it uses its claws at the tip of its
hind legs to grab the platform and
anchor itself while it swings its body
back down
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now even though these roaches can jump
it doesn't mean they're particularly
good at it here's another one facing
that same gap to get across this one
pairs a jump with a flutter of its wings
but it only manages to barely make it
across the gap it lands face first
bouncing its head off the platform
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the roaches in this video are super
common and they're some of our most well
studied insects so i think it's cool
that there's new things to observe and
learn about their behavior
we're just getting started studying this
aspect so you can expect more roach
videos on this channel in the future but
thanks for watching this one
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you