Plants produce nectar for insects and birds generally so as to enhance pollination.
Pollination requires that pollens move from the anther of a flower to the stigma of the same or another flower. The reproduction of plants depends on pollination.
Since plants cannot themselves move their pollen from the source of production, the anther, to the stigma, they depend on external factors to carry out the task. One of those factors is insects/birds.
The production of nectar by plants attracts these organisms and in the process of feeding on the nectar, they move some of the sticky pollens about and end up transferring them from the anther to the stigma.
More on pollination can be found here; https://brainly.com/question/1675149?referrer=searchResults
