It describe instinct behavior which was described by Charles Darwin in his book origin of species. Darwin observed this behavior or collected from others who had observed this

1. AL-MAMUN
11th batch
JAGANNATH UNIVERSITY

2. INSTINCT
Charles Darwin tried to explain the closest definition of instinct – ‘An action which we
ourselves require experience to enable us to perform ,when performed by an animal more
specially by a very young one without any experience and when performed by many
individuals in the same way without their knowing for what purpose it is performed is
usually said to be instinct’.
Darwin believes that inherited habits, those
learned by parents and subsequently passed on to
offspring by hereditary inheritance, may play a
role in the construction of the instinct of animal.
Example- Hammock making behavior of Caterpillar
, egg laying behavior of Cuckoo etc .

3. Instinct In Domesticated Animals
Domestic animals vary in their mental qualities. These variations of instincts can be inherited
or may be influenced by curiosity.
In terms of cats according to Mr. St. John one brought home
game bird another hare or rabbit and another hunted on mar-
shy ground and almost nightly caught woodcocks or snipes. We
should assuredly call these action natural instinct.
Domestic instincts, habits and disposition are so strong and
inherited.
A crossed between Bulldog and Greyhound has given to a whole
family of Shepherd dogs which have a tendency to hunt hares.
Most of the natural instinct lost under domestication.

4. Instinct of the Cuckoo
Egg laying behavior of cuckoo is inherited and it’s a great example of instinct . Cuckoo lays
her eggs not daily but at intervals of 2 or 3 days. So they were to make her own nest and
sit on her own eggs those first layed eggs hatch firstly and different aged young found in
the same nest .For this reason cuckoo lays her eggs on others nest.
An Australian cuckoo lay one egg in a nest, it
is not rare to find 2 or even 3 eggs in the
same nest.
In European cuckoo, the offspring of the
foster-parents are commonly ejected by
themselves within two or three days after
the cuckoo is hatched.

5. Slave-making
InstinctThis remarkable instinct was first discovered in Formica rufescens by Pierre Huber . This ant
absolutely dependent on its slaves .The males and fertile females do not do any kind of
work .The sterile slave making their nest , feeding their larvae and determine migration.
Another species Formica sanguinea the
males and fertile females are differ from
their slaves in colour and behavior. The
master always remain in the nest and
slaves do their all kind of work.
Different types of instinct also found in F.
sanguinea in Switzerland .The slave and
masters do work together.

6. Bee hive-making Instinct
Darwin observed ,examined and combined all the work done on bee hive in this part .
Pierre Huber has done research on melipona domestica hive .It forms a nearly regular
waxen comb of cylindrical cells , in which the young are hatched and latter cells nearly
spherical and of nearly equal size cells for holding honey .
Beyond this stage of perfection in
architecture, natural selection could not lead;
for the comb of the hive-bee, as far as we can
see, is absolutely perfect in economising
labour and wax.

7. Objection to the Theory
Darwin admits that habit may play some unknown role in the development of variation.
He provides an example of hereditary characteristics the birthing of sterile worker ant
that the differ in shape, size and habit from the male and fertile female . Since the
variation is inherited but Darwin could not give any proper reason for this.
Although Darwin can not pinpoint the means
by which these variations are created but
Mendelian genetic mutation theory provide
the answer.

8. Conclusio
nDarwin’s discussion of advantageous mental characteristics in animals
implies that organisms have intelligence and that some use this
intelligence to survive better in nature.
Basically he tried to explain that instinct and survival of animal in nature
is directly connected to each other .

9. Thank you