Many nestlings produce faeces that are surrounded by a membrane. These so-called faecal sacs are white with a dark, pointy end. Nestlings signal to their parents that they are about to defecate, e.g. by lifting their bottom. This allows a parent to pick up the sac straight from a nestling’s butt and remove it to keep the nest clean. Nestlings usually produce a faecal sac immediately after being fed, but if they fail to do so, the parents peck their bottom to encourage defecation. Parents sometimes eat the faecal sacs instead of removing them. Nestlings stop producing sacs when they leave the nest.

https://www.youtube.com/watch?v=_0PUkUctuoE

Never mess with bombardier beetles! The beetles are famous for their explosive way of defending themselves. If threatened by predators, the beetles eject a 100°C hot chemical spray from their anus which is accompanied by a popping sound. For toads, beetles are usually a tasty snack. But bombardier beetles know how to fight back, even from the inside of a toad’s stomach. By releasing their boiling hot spray, toads are taught a painful lesson and made to regurgitate the feisty beetle.

https://www.youtube.com/watch?v=BWwgLS5tK80

Nymphister kronaueri is a tiny, reddish-brown beetle native to Costa Rica. It lives exclusively among the nomadic army ants of the species Eciton mexicanum. This tiny beetle has found an unusual and rather lazy way of transport. Whenever the ant colony moves on, the beetle attaches itself with its mandibles to the waist of an ant, hitchhiking all the way. It makes the ant look like it has two abdominal segments, one above the other. It’s a quite dangerous ride though – army ants are aggressive predators, dismembering and consuming other insects, spiders, and even scorpions. Looking like an ant’s butt helps reduce the chance of being detected. Photo by Daniel Kronauer

https://www.esf.edu/top10/2018/04.htm

The illegal ivory trade causes elephant populations to diminish at an alarming rate. To access the tusks, poachers kill elephants by either poisoning or shooting them. In March 2018, Singaporean authorities seized more than 60 bags of ivory worth around AUD$3.3 million from a Vietnam-bound ship. Conservation biologist Samuel Wasser extracted DNA from the elephant tusks and compared it to DNA he had previously collected from elephant dung across Africa. As a result, Wasser was able to pinpoint exactly where the animals had been killed, and he discovered that ivory shipments came from a few poaching hotspots. This was valuable information in the fight against ivory poachers and corrupt wildlife rangers.

https://blogs.scientificamerican.com/extinction-countdown/poachers-versus-poop/

In Alaska, defecating brown and black bears, not birds, are the main distributors of berry seeds. By dispersing the seeds through their scat, bears unintentionally promote the growth of the berry‐producing shrubs that feed them. The scat of a single bear can contain tens of thousands of seeds. The seeds are then further spread by small mammals which bury them in the ground. Brown bears disperse the most seeds. During the summer months when their diet switches from berries to salmon, black bears temporarily take over the role of main seed dispersers. A drastic reduction in bear numbers in Alaska would very likely cause a reduction in berry‐producing shrubs, changing the ecosystem.

https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.2076