The intelligence agencies usually calls them bugs because they usually annoy persistently.

The plural of intelligence is intelligences.

As in "the intelligences were shared between agencies".

I don't believe that there were any organised intelligence agencies, although there may have been. I do know that none of the Intelligence agencies in the UK today existed at the time. They would definitely have used spies and informants however.

No, the indian intelligence agencies are looking for him.

FBI, CIA, NSA.