Changeling Headcanon

- Changelings do eat physical food. They can't survive on only love anymore than a plant can survive on only sunlight. Not requiring calories does substantially cut down on how much food they need though.

- There is no "hive mind." Changeling's are individuals, though they do live in colonies that can roughly be described as "hives."

- Each hive is rather small, no more than a few hundred. This is out of necessity, as a hive can't grow too large without straining against the limits of its resources, namely the amount of love available.

- Generally, changelings don't collect love from the family or friends of those they impersonate, as that is reckless and far too cumbersome to provide a steady supply of love. Instead, they use their shape shifting abilities to trick and kidnap ponies. They then cocoon their victims and force them to play out dream-like scenarios designed to draw out the emotion of love- which is then sucked out for use in the hive.

- The necessity to kidnap and cocoon members of other sapient species means they must tread lightly, as too many disappearances will alert their prey species to their presence. This severely limits the amount of love available for any hive.

- There are many hives, spread out to avoid interaction. When hives do meet it's often to lay claim to any given feeding ground. Generally they will jockey for position, posturing until one proves to be submissive and backs down to find new territory to lay claim to. Confrontations are generally avoided out of enlightened self-interest, as any battle between the two may reveal their presence. That said, confrontations do sometime occur, which has led to bitter rivalries and hatreds.

- Prior to A Canterlot Wedding changelings were geographically isolated from Equestria and the surrounding nations. Indeed, changelings were unheard of in that region of the world. Chrysalis lead her hive into new lands in hope of finding potent new food sources, which she succeeded at with the discovery of Equestria. Even now, the "new world" of Equestria is unknown to other changelings- though more are sure to follow in Chrysalis' hoofsteps eventually...

- Changelings are not inherently evil, but their biology forces them into an antagonistic relationship with other species. Overtime, this biology influences social attitudes, encouraging changelings to view other species as a source of food rather than individuals with their own lives.

- "Feeding" on an individual of any species does not necessarily cause harm but excessive feeding is equivalent to massive blood loss.

- "Friendship is magic" is quite literal, as intense or deeply felt emotions can be used to generate magic- and hence usable energy. This also applies to negative emotions, but their use for magical energy is inherently dangerous. Because of this, changelings evolved to only be able to use positive emotions.

- At the higher end of the consumable spectrum of emotions there is fully-fledged love, and at the lower are simple feelings of compassion and sympathy. Naturally, stronger emotions generate more energy, and hence more food.

- Changelings can only sense emotions directed at them specifically, whether they are disguised or not.