Feeding a flumph

My players have have decided to befriend a flumph.

Flumphs feed by siphoning mental energy from psionic creatures, and they can be found lurking near communities of mind flayers, aboleths, githyanki, and githzerai.

None of my players have natural psionic abilities like mind flayers do. How might they feed their flumph?

Beyond creatures with natural psionic abilities, what other spells, abilities, etc would provide sustenance for it? I’m looking for anything RAW or RAI as to suitable spells etc, or anything else from lore about how flumphs feed.