They have been trailing us for years. We know that. In fact there is little we do not know about their activities because we see everything. They are clumsy. Sometimes when we watch them we pity them in their struggle for understanding. Their cameras and computers are a heavy load in rough terrain, while we are assured as we rise from the jungle to the colder plains at the foot of the mountains. They do not mean harm. You can see it in their eyes. But more will come after them. More and more. And that is what we fear.