Once it is discovered you can then move it, in steps to another location. Hummingbirds remember where their source of food is. In general, hummingbirds can be expected from April through October in most of the country. The greatest activity might not be experieced at the beginning of the season when females are nesting and caring for their young. When the new generation of hummingbirds leaves the nest, usually from June through July, an increase in numbers and activity may be noted at feeders until the birds head south for the winter.
Migration is a strong instinct.
Leaving feeders up will not deter the start of migration and may help the laggers.