400
Among the compounds identified , several play a role as semiochemicals for many animals , and 28 allomones , 43 pheromones , 21 kairomones have been identified .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None