they also escape feral children, and might escape animals for mundane reasons, like their not having critical periods long enough to learn these aspects of language.
On the other hand, humans having learned language at late ages (e.g. Helen Keller having learned it at 6) suggests that learning language during the critical period isn’t a necessary requirement. (the Wikipedia links claims that deaf people who learn language at a late age never master it completely, but assuming that it hasn’t been edited by others, the quoted Keller excerpt gives a rather different impression).
On the other hand, humans having learned language at late ages (e.g. Helen Keller having learned it at 6) suggests that learning language during the critical period isn’t a necessary requirement. (the Wikipedia links claims that deaf people who learn language at a late age never master it completely, but assuming that it hasn’t been edited by others, the quoted Keller excerpt gives a rather different impression).