Board Thread:Questions and Answers/@comment-208.174.57.186-20121208051539/@comment-3329304-20121209060454

Sorry about it. I didn't get any info regarding it in the anime but recently found out on the manga. The basic difference is in transmission process. If the human gets direct transfusion from queen, he/she is likely to become a chevalier. And if the blood is injected via any third party or manipulated (like making into delta particles), it'll create a chiropteran. Hope it's clear now :D. See here for more info: Chiropterans and Chevaliers.