Deb1 said "It seems that there is some kind of small animal trapped in the attic. Not sure from where it has gone there. How may I know what is it and get rid of it? "
When that happen to someone I knew, they put a cat in the attic for a few hours, for a few days in a row, finally worked for them.
Unorthodoxed , but worth a try if it doesn't gross u out.
Since they may bring it back to u as a gift. yuk
Good luck