system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do spiders initially connect the first couple of threads to surrounding objects?

Specifically, I've seen spiders with threads connected to a street sign > to a tree > to another tree, etc.

 Does the spider crawl along the ground? Wouldn't the original strand become tangled?
gpt
Usually they will attach the line at one end, drop down, then walk across and up, extending silk all the time. Then they'll attach a new line at the other side, and eat the first line up while using it to get back across the gap, extending the new silk at the same time. In this way they create a line with the correct tension. 

They will then usually travel back along the line and drop a vertical one down to the ground from the halfway point to make a Y shape. The rest of the web can then be built around this.

Some spiders make a sticky 'kite' of silk at the end of a line and float it across a gap until it sticks at the other side, then proceed as above.