If you thought that or vegetarianism were the only options available to vision-impaired animals, you鈥檙e in for a surprise.
(the plural 鈥減latypus鈥� is also correct, but technically 鈥減latypi鈥� is not) have almost 40,000 special cells in their bills called that are activated by This is quite useful for the platypus, who tend to live in murky or dark waters but are able to to catch their dinner.
It鈥檚 not only platypuses that can sense electricity: there are many that also do this, as well as some,, and a!
While platypuses might not be blind, they are functionally blind when hunting. They close their eyes, noses and ears whenever they dive, and then swing their heads back and forth to sense electrical currents and move towards them ()
But why are there only 3 species of mammals with these electric abilities? Well, it鈥檚 partly due to ecological niches. If a species develops a method to hunt where no others can (like in dark murky water) they flourish, but since that niche is now filled, the new skills don鈥檛 extend beyond that species.
Otherwise, you can thank evolution for non-electric animals. Sensing electric fields is only really useful if you live in the water (like electric fish) or at least hunt in it (like platypuses). Once you live and eat on land, there鈥檚 no real reason to keep your electroreceptors, and with less water comes even fewer reasons. This is: Western long-beaked echidnas have about 2,000 electroreceptors on their beaks (20x less than platypuses), and the short-beaked echidnas, who tend to live in even drier climates, have only about 400.
It鈥檚 worth pointing out, though, that all animals聽use electric signals to make their muscles work, so in a sense, we鈥檙e all electric!
