What is "incubators"

Usage examples of "incubators".

They were surrounded by other incubators, with other little sick babies.

Periodically it flew northward to meet floatwood islands coming along the Meral, sought out the incubators installed on them, left one of its leathery eggs in a seed pod on each, finally returned to its cold skies.

She wondered if Graham was feeling that also--wondered if he was looking out at those babies in their incubators and thinking that some woman had managed to carry and bear each one.