6999
Thus , some species differences involve the encoding of social stimuli as different neural activation patterns within the AVT / AVP network , whereas other behavioral differences arise downstream of this system .
 Chemical: AVT; Chemical: AVP
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: AVT; Chemical: AVP