Related by context. Frequent words. (Click for all words.) 68 echolocation 61 toothed whales 57 odorant receptors 55 mammals 54 reproduce asexually 52 Sperm whales 52 echidnas 52 vocalisations 52 olfactory receptors 52 amphipods 52 otolith 52 narwhals 51 zebra finch 51 sexual dimorphism 51 convergent evolution 51 vertebrate animals 51 sensory organs 50 vocalizations 50 opportunistic feeders 50 ganglion cells 50 zebra finches 50 rustling leaves 49 melanogaster 49 flapping wings 49 katydids 49 placental mammals 49 hydrophone 49 damselfish 49 marine invertebrates 49 insects spiders 48 sea anemones 48 toadfish 48 Indohyus 48 pectoral fins 48 unicellular 48 nematode worms 48 otoliths 48 homing instinct 48 baleen whales 48 symbionts 48 eiders 48 circadian clocks 47 larval stages 47 fluorescently labeled 47 soundwaves 47 crocodilians 47 mantis shrimp 47 motile 47 tailless 47 vertebrates 47 slime molds 47 voracious eaters 47 planktonic 47 morphologically 47 mammal 47 neural circuitry 47 hydrophones 47 zooxanthellae 47 plesiosaurs 47 rhodopsin 47 dorsal fins 47 retinal ganglion cells 47 mole rats 47 underground burrows 47 nocturnal creatures 46 rabbits squirrels 46 mouthparts 46 birdcalls 46 theropod dinosaurs 46 ultraviolet wavelengths 46 baleen whale 46 beaked whales 46 tunicates 46 Drosophila melanogaster 46 nonhuman primates 46 Fruit flies 46 humans 46 nocturnal animals 46 mammals reptiles 46 sonar 46 winged insects 46 narwhal 46 pileated woodpeckers 46 olfaction 45 aquatic invertebrates 45 neurones 45 mammalian species 45 sonars 45 kittiwakes 45 flatworms 45 cochlea 45 hind limbs 45 petrels 45 habituate 45 mandibles 45 sticklebacks 45 avian species 45 reproduce 45 mockingbirds 45 magnetic compass 45 species