Yiddish: He's got pins in his behind.

He can't sit still. He's restless.  SOURCE: Bernstein, Jüdische Sprichwörter und Redensarten.  Compare:

He's sitting on pins.   |   Er zitst af shpilkes.   |   .ער זיצט אויף שפּילקעס

SOURCE: Stutchkoff, Der Oytser fun der Yidisher Shprakh

ער האָט שפּילקעס אין תּחת.

Er hot shpilkes in tokhes.

He's got pins in his behind.