The human does something unexpected

Everything is progressing exactly according to the Zamba's plans. That is, until the ninja calms herself, focuses inwardly, and pushes her ki perception downwards.

Before the Zamba can react, its Sensory Deprivation Field is slightly broken through, and the human is able to feel some of what is happening down below. She is unable to use her nerves, but she can now feel much of her arousal. And there is a lot of arousal to feel.

The ninja has no idea that she is currently lactating, pissing, having a nipple penetrated, having her asshole probed, or full to the brim of rapidly growing Zamba larvae, but she does know that something is horribly wrong, and it appears to be of a sexual nature.

This is enough for her to use the rest of her available ki to perform a ki-enhanced yell out for help. The Zamba may only have a minute or two to successfully reproduce, before this human is rescued. And there was so much more that it had planned! How disappointing... Assuming someone does come to her aid, this ninja has really gotten quite lucky, hasn't it?

Still, the Zamba doesn't have time to dwell on feelings of disappointment right now - it has a job to do.