They were small and surely relied mostly on smaller animals such as large birds and rabbits and snakes for that matter. Their critical weapon would have been their throwing arm. With that they went wherever they were able to walk or swim.
What they did though is fill every available corner of Eurasia and Africa for that matter. With that base in place, every new genetic improvement such as larger brains and better teeth easily spread world wide in a few centuries. H.Erectus is an obvious successor species.
What we do have is a persistent and successful little people that did go global a long time ago and may well have walked into North America.
We also have reports of their existence that need not be ignored as well. They would have mind to mind communication and ample reason to avoid us. We are not really looking for them and they certainly avoid us if they still exist.