Angels are pretty much impossible to sex. Especially when they're small. Even "experts" sometimes get it wrong. I think you're supposed to hold them up to a light and look for a silohette (sp?) of something in their genital region, but I can't remember what and the difference is very slight between the genders. You CAN tell once you've got 2 that pair up, if you watch them spawn, but other than that it's really hard. But, since all angels act the same, it doesn't really matter if you only have one.