Open-fronted Orb Weaver Exhibit

Does anyone know how they stop the spiders escaping?

Hey Pat, I saw an exhibit of an open orb-web spider at the Smithsonian National Zoo last year and wondered the same thing. According to their website orb-spiders do not leave their webs and this is why they can be displayed in open exhibits: Madagascar Golden Orb Spider - National Zoo| FONZ

That's handy. Zoos would be a lot less complicated if animals just stayed where they're supposed to.

In many cases in zoos the barriers are there to protect the animals, too.

But they can't all stay in their nests for their entire lives, they would have to travel to breed wouldn't they?

Unless just one sex travels to breed (males probably) and the other never ever leave the nest, and are the sex displayed.

The males orb spider are tiny and live as semi-parasited on the female nest (she is app. 1000 times bigger). There might even be several males on a single female web. males may travel long distances by wind.