"Higher species" or "higher forms" was a term used to refer to species who were aware of the Time Lords and the Last Great Time War. Doubting the Tenth Doctor's identity as a Time Lord, the Shadow Architect stated that the Time Lords were the "stuff of legend" and that they belonged in the "myths and whispers" of the higher species. (TV: The Stolen Earth)
According to the Gelth ambassador, the Last Great Time War was devastating to "higher forms" yet invisible to "smaller species". (TV: The Unquiet Dead)