does size matter?

I recently found out about this parasite that infects amber snails that turns it into a zombie snail by attacking it's central nervous system. This parasite directs the snail to head toward the sunlight and pokes itself through the snails eyestalks, waving like a tasty maggot, so birds can attack and eat it. It lays eggs in the birds digestive tract which are then shit out so snails can eat the droppings and repeat the cycle. It's interesting to note the bird isn't attacking the snail but the maggot look alike parasite inside the eyestalk.

This got me to thinking... Are my own parasites somehow directing my movements like the zombie snail? Is the snail moving into the sunlight to be eaten because it's a zombie taking orders or to commit suicide? If a non-biped, non-humanoid space alien were to make contact would it try to communicate with me or the car I was driving? If the same alien were to make contact would it try to communicate with a hotel or the people inside? Doesn't it make sense that if a real, honest to god, different as all hell, space alien were to pay a visit, wouldn't it try to communicate with my parasites, viruses, bacteria, and other life forms rather than their abode?

From one office building to another, don't you feel just a little insignificant?