84599
Significantly , the system does not rely on the hardness of the exoskeleton , as many other arthropod sounds do , meaning that the spiny lobsters can continue to produce the deterrent noises even in the period following a moult when they are most vulnerable .
 arthropod
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 arthropod