Ah, I'm sorry about the confusion. It's not very clear, but you need to solve all the previous locations for them to arrive at the house. In other words, you need to get a blue spiral symbol instead of a red X at all locations except the rightmost one on the map. Then, the seed and the creatures will appear at the house.
I believe you have the lake left to solve? A hint is that the "shovel" is supposed to be an oar.