... play back samples of speech when a shadow falls across them. The covers are held on by security hex screws. The tamperproof covers reveal a stack of AAA batteries, a wee speaker and a board about the size of an Arduino with a Winbond W58300 sound chip, a TDA7052 audio amp and a socketed 8-pin EEROM chip.
Allegedly.
'Nuff said.
'tamperproof' you say?