Page 84 - One Million Things: Animal Life - The Incredible Visual Guide

INSTINCT
WEB SPINNING
Spiders have special glands for producing

Everything an animal does—and the way in which it does strong silk threads. Orb web spiders use silk to
it—makes up its behavior. Some behaviors are learned during build spiral webs that catch flying insects.
an animal’s lifetime, but many are inbuilt or instinctive. They After constructing a “scaffold” of dry threads,
trapping threads. Spiders do not learn to do
are performed automatically in situations such as courtship, the spider spins a spiral of sticky, insect- Spoke threads
travel from
by instinct, even when they have just hatched.
breeding, or nest building. this. They can build the most complex of webs outside to the
center of
the web

1.

Spider
anchors line
Free-floating
of silk and
silk dragline
pulls it tight
catches twig
Spider lays
down a spiral
of sticky
threads

Spider trails
Vertical
out second
thread pulled
horizontal
downward to
thread
create “Y” scaffold
2.
5.

Additional
threads frame
the “Y” scaffold TURTLES
Female turtles instinctively
3. emerge from the sea to lay
their eggs, so that their
offspring will breathe air
when they hatch. The eggs
are laid in a hole dug in
the sand, which is then
covered up. A few weeks
later, the eggs hatch.
The hatchling turtles
4. automatically dig
upward, then
dash straight toward
the open sea.

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