Ultrasound in Adult Rodents

PRODUCTION of ultrasound by baby rodents has been reported by Zippelius and Schleidt1 in Apodemus f. flavicollis Melchior, Mus musculus domesticus Rutty, and Mictrotus a. arvalis Pallas, and by Noirot2,3 in baby mice, Clethrionomys glareolus Schr., Mesocricetus auratus Waterhouse and albino rats. I have now confirmed this phenomenon for the young of Clethrionomys, Mesocricetus and laboratory rats and mice, and extended it to the young of Acomys caharinus (Desmarest), Meriones shawi Rozet, M. unguiculatus Milne-Edwards, a species of Gerbillus, Apodemus sylvaticus (L.), Mus minutoides and a species of Thamnomys.