The world’s first robot zoo opened this summer. Artist Leonel Moura designed 45 solar-powered robots for an outdoor installation in Portugal called Robotarium X. The autonomous bots roll, wiggle, and mingle inside the 13-foot-high steel-and-glass enclosure. When the sun sets on their canary-yellow cage, the machines simply grind to a halt and sleep until morning.

Three robo-models stand out in my mind. They range from neat, to cute, to horrible. I bet you can guess which is which.

Cursovigilo (right) – These curious critters chill by the windows of the Robotarium, waiting for visitors. When a gawker approaches the glass, the Cursovigilo – which look like penguin-potato hybrids – lock on and bobble their heads to mimic the spectator’s actions.

Araneax (left) – This is the largest and certainly creepiest in the robot kingdom. Black, barb-like hairs jut out of its seven wiry legs, which lift the automated arachnid to about the height of a human. For reasons that are beyond me, they’re programmed to be aggressive and to fiercely defend their territory. The Araneax lurk on the ceiling of the Robotarium, where no other bots can reach, and jealously survey their space. If a foolish bot wanders too close, the spiders descend to scare off the intruder. Terrible!

Zoid (below) – The bittiest of the bunch, these primitive, solar-powered bots scamper between the big guys. If they stray into a shadow, the tykes shut down. Trapped, the zoids lay dormant in the shade until another robot bumps them back into the sunlight.

For me, the Robotarium evokes conflicting emotions. I’m half delighted – imagining sprite-like Zoids flitting around my house, cleaning my kitchen with their Roomba cousins. I’m also terrified – imagining a droid dystopia in which armies of Araneax invade, tearing my house asunder. Good thing these Portuguese robots are locked up – for now.