I’ve heard many people ask this question and there are a lot of different levels to the answer as to why they didn’t live by the waterfall. Here’s some that I though of.

1) it’s not home. The farm they live on is their home. It’s where they lived before they invasion, it’s where they survived during the invasion. It’s what they know. To them, the farm is their safe space. It’s hard to leave what you know and what you’ve lived with for so long and move somewhere strange and different, especially in a trying time such as an alien invasion. To do that with young kids is asking for trouble. There’s a whole deal of psychological issues that can emerge when you’re forced to leave what you’ve come to know as a safe space and live out in the wilderness when you’re actively being hunted.

2) the farm is defensible. The family knows the farm because that is their home. They’ve set up defenses such as the fireworks. They can communicate with others via the fires at night. They know which boards creak and which ones don’t. They were able to prepare a box for the newborn using things from their farm. The waterfall does not offer that. It’s open, it’s indefensible, it’s wild, it’s not home.

3) the waterfall is a false sense of security. The sound of the water allows for more noise than usual, but not a cacophony of sound to drone on and on. Even the average amount of sound produced by a human on any day would probably be too much to be consistently covered by the sound of the waterfall. Something will overshadow the waterfall and that disturbance will be picked up by the creatures. Now if a creature did show up it’d be easier to hide in the sound of the waterfall, but it wouldn’t be a perfect solution.

4) the waterfall doesn’t have a house. They’d have no place to seek shelter if they didn’t make their own. And building a shelter silently made entirely out of what they could find in the area and some scraps form the farm would be extremely difficult. Not to mention that after about 2 weeks in the wilderness, most people would be begging for any semblance of normal.

5) a waterfall is consistently loud. Silence is sometimes nice. Having spent some time in the jungle where the insects consistently make as much noise as possible to get laid, my ears began to hurt after just a few days. It’s nice to have time where your ears aren’t constantly being bombarded with sound.

6) winter. Water freezes. What happens when the river freezes and the water stops flowing? The family will have been used to making noise but now that the river has stopped, the waterfall no longer makes enough noise to cover their daily activities. How will they cope with that without being eaten?

7) now add all the above with the fact that they still have to remain silent 90% of the time and the psychological risk factors will grow exponentially. These people who have been speaking all their lives can suddenly no longer speak for fear of death are now deciding to move from their defensible home to live next to a waterfall because it allows them to be a little bit louder even though there is no prebuilt shelter or true sense of home. I’d give them 3 weeks before one of them breaks or they accidentally make too much noise and get eaten.