And I thought this problem (people trying to be bats and being sick) only affected cows

JuanMaria, you are so very nearly right. Some of these Bat forming groups couldn't decide if they wanted to be bats or cows, so tried both, and became known as Batty Cows, and thence to Mad Cows. Over most of the countryside however these people are known as "Cow Bats".

Rod