Depending upon the species, spiders can make more types of silk: strong, soft, sticking, sensing, etc.

Most spiders have terrible eyesight despite having eight eyes. Those with good eyesight are jumping spiders, portia, and a few ground spiders. These species are easily distinguished by having two large front-facing eyes.

Due to bad eyesight, most spiders use touch through their webs and/or hairs. The hirsute species can easily identify pretty much anything that causes a wind current near them, and most all species can easily identify prey by the distinct vibrations they make once caught in the web.

If you watch most spiders, however, they can occasionally be fooled on windy day when a leaf or other detritus hits their webs, and they have to go touch it to find out it isn't prey. Eyesight just isn't a thing most are great with.

Most of spiders I tried to fool can't be fooled by a leaf, they usually wait for recurring vibrations. Touching the web by a stick never produces enough good vibration to attract the spider. Baiting to things on the web is mostly about young spiders, the biggest spiders I have seen on their webs usually kind of lazy.