someone help me :(

[rOnz]

So i introduced my 12 months old female to my male , and the female doesnt any aggression , so i put my female into my male cage and she still showing a bright colour and seems receptive , but after my male grabed her she start to showing a little dark colour and after 3 minutes she's starting to hissing and bite my male ,

so i separate them now , is it normal when a female look receptive but showing a little aggression when mating ?

 

[Eltortu]

A receptive female will show no sign of aggression until the deed is done...