Eli5 – How do spiders create webs horizontally?



I don’t mean at a corner of a wall.
Instead, something like:

Between two (close enough) tree trunks.

Across a garden walkway between two hedges.

Even once across my door frame, which caught me like a fly

I get that in some cases, like an outdoor area, the spider can use the wind to carry the web. But between two tall hedges and across my door frame don’t make sense.

In: Other

Wheel web spiders start their webs by just letting out a long thread and letting airflow move it around until it catches somewhere else. Then they traverse the line to span more lines as the basis of a web.

You’re talking about the wind but spider silk is so light that even a very light airflow or draft can carry it across. A house or a hedgerow still allows for plenty of airflow to move a 0.0003 mm thick line of silk.

Spiders evolved this behaviour because flying insects essentially ‘surf’ flowing air. Building a web by letting the flow of air in a space dictate where the web ends up has a higher catch rate.