Bats roost in many of the bedrooms at Cackle's Academy, as the bedrooms have no glass in the windows. In Mildred's fourth year, all the pupil's bedrooms are fitted with glass in the windows, complete with Bat-Flaps so the bats can still get in and out. Mildred has three bats in her room, which she has named Winky, Blinky and Nod.
Maud Moonshine has a pet bat, Barney, that she got her birthday in her first year. Barney lives in Mildred's room with Winky, Blinky and Nod. Beatrice the bat lives in the library at Cackle's Academy (The Lost Chord).
Mildred's bats, Winky, Blinky and Nod, are named after the three little fisherman in the poem 'Wynken, Blynken and Nod'. The names refer to the closing eyes and nodding head of someone falling asleep.