Question about pollinators in greenhouses

When I was writing about the possible option of greenhouse for growing strawberries in this week assignment, I was wondering what do people do about pollinators for the greenhouses? Do you always have to have a beehive for greenhouse if your plants are not selfpollinated? Could you just open sides of it (somehow) and will it be enough for pollinators to fly in, especially here in Alaska? Could you somehow attract pollinators to get in greenhouse? I saw somw ideas of electrical pollinators, but it looks like a lot of work for any decent size greenhouse….