the knot is indeed a bird. although strictly speaking it is not a migratory one in this country rather it is a "winter visitor". OK, the difference escapes me. however, I am certain that it has never been observed trying to tie granny knots in pieces of string or old rope that it finds on the beach. if it tried any it would surely be a reef knot (to continue the seaside thing). and as every boy scout knows a granny knot is a failed reef knot in any case. I hope that clears things up.