Males of the shrimp Penaeus vannamei perform the first three stages of mating behavior with immature females, but do not actually inseminate females unless they have ripe ovaries(Yano et al., 1988) Mature spiders(Anelosimus studio sus) also appear to"practice" mating in a similar manner, which benefits them in subsequent encounters with mature females however. they also do not actually transfer sperm to the immature females Pruitt and Riechert, 2011). While"practice" may similarly benefit a male lobster by attracting other females to his shelter(Atema, 1986) it would be a waste of potentially costly sperm to actually pass a spermatophore to an immature female fDewsbury 982). In contrast, it would benefit an immature female to molt. mate, and then receive protection from a male while her shell hardened possible that