Though sponges may occasionally be detrimental to organisms, many creatures live in symbiosis with them. Sponges are excellent filters, generally passing the equivalent of more than 60 glasses of water through their systems each day, and various aquatic animals exploit them for this characteristic. Also, sponges tend to have an objectionable odor and taste, and some varieties are poisonous as well. Small creatures, such as certain types of hermit crabs, frequently carry sponges to discourage predation, sometimes even using them as camouflage.