Cricket balls could easily bowl over a series of maidens, researchers have found. Biologists from the universities of Derby and Cambridge have discovered that the tuberous bushcricket has the largest testicles proportionately of any species, accounting for 14 per cent of its body weight. But unlike in other species with promiscuous females, the testes do not produce abnormally high concentrations of sperm. Karim Vahed, reader in behavioural ecology at the University of Derby and leader of the research, said of the testes: "They allow males to transfer relatively small ejaculates to a greater number of females. Males don't put all their eggs - or rather sperm - in one basket."