We analysed seismic signals in two spalacid rodents, the giant root-rat (Tachyoryctes macrocephalus) and Gansu zokor (Eospalax cansus), displaying a different degree of fossoriality. Both produced seismic signals during the peak of activity, probably as territorial advertisement. Comparison with other spalacids did not reveal a relationship between inter-pulse distance and body mass; although this relationship appeared after the giant root-rat, the largest and most fossorial species, was excluded. All hitherto studied spalacids produce seismic signals by head-thumping, which probably evolved as a ritualization of soil tampering, an interesting case of convergent evolution of communication in rodents.