Det finns is more for when things exist constrasted to not existing. Such as ”det finns två bröd kvar” (’there are two loaves of bread left’; and then they’re gone!) In this case, it’s just a bee that has gotten into the kitchen, so it’s better to use det är.
So we use det är if a thing exist in a place but it should not have to? thanks a lot. I think reading books will make me get used to it.
Well, we don't use bi like that, but even if we did it would be en. :)