Do males always leave behind yellow stuff after breeding?

I'm pretty sure my pair bred this evening. My male has been ready to go for several weeks already, but this was the first time my female was receptive. They were both laying still with the male on top of her and they appeared to be locked, with tails all entwined, but I didn't want to disturb them to really check closely. They separated after a few minutes but my male was still really chasing her around and trying to get his tail around hers, but she wasn't having it anymore. I separated them, but didn't see any of the yellow leftovers that males generally leave after breeding.

Spillage is usually but not always left behind after a successful coupling. Given the number of animals I pair I don't have sufficient time to watch every hook up. Therefore I breed my animals in bins with paper towel liners in hopes of catching the telltale spooge but I have, over the years, observed locked couples that leave no evidence of success.
As for the chasing after, I would think that would indicate that they had not locked up. Usually after a successful breeding, the pair disengage and go their separate ways. I've never had continued "courting" after a lock up.
I'd say keep trying with those two.

Good Luck,
Terri

Thanks Terri! I am definitely going to keep pairing them. The female actually hasn't even had her first shed of the year yet, but I thought I would see if she was receptive anyway. One other thing was that when I was putting her back, I did notice that her anal scales were slightly folded in, exposing a little bit of the soft flesh of the tail, so I carefully unfolded them. But I was thinking that was an indication of penetration as well. Do they ever have incomplete locks? My male is also a virgin, but I don't know if that matters.

I used to put fresh paper down in the cages whenever I introduced males to females, and the stain left behind was a pretty reliable indicator of mating activity. But is it 100%? Probably not. As I certainly got gravid females even with no physical evidence of mating. As a rule I tended to have males attempt to breed females until there was some positive evidence, just for insurance sake, but I wouldn't be surprised if there was a mating, regardless of lack of evidence.

At the beginning of breeding season, I would put white stickon dots of the cages of all eligible females. For each confirmed breeding (I often used multiple identically genetic males for each female) I would put a yellow dot on the females cage. Three yellow dots and that was enough. When she went into her pre egg laying shed, I would put on a blue dot. When she had that shed, then a red dot would do on and an egg laying box would go into the cage approximately 5 days later.

Obviously it was a lot of work when you are talking about hundreds of snakes! Occasionally I will get nightmares about it.