THE Indian neem tree does not like insects. The neem makes it clear to all insects that they can go elsewhere if they are looking for food. It is very rich in a substance called azadiractitin found in all parts of the tree. This is not palatable to insects and they go elsewhere leaving the neem in peace.
Scientists spray an extract taken from the seed of the neem tree on other plants to give them protection against insect attack.
Now you know why your grandmother used to leave a bunch of neem leaves in the gunny bag of rice stored for future use!