What's happening to the cats?

That might not have been everyone's first thought following the defeat of Stephen Harper's government Oct. 19, but the non-human inhabitants of 24 Sussex Drive must also make a transition with the arrival of a new government.

And so, the Harper family pets — cats Stanley and Gypsy, as well as Charlie the chinchilla — are heading west as the rest of the household begins its next chapter in Calgary.

But those weren't the only furry inhabitants at the prime ministerial abode.

Laureen Harper is a keen supporter and advocate for animal causes, including the work of the Ottawa Humane Society. When the organization officially opened its new shelter in 2011, the prime minister and his wife were special guests.

Part of the private bedroom area of the prime minister's official residence was used to foster animals awaiting adoption.

Pet started as foster animal

While the Humane Society won't disclose information about specific volunteers, the prime minister's communications team has disclosed that the family fostered dozens of animals since the Conservatives first formed government.

The prime minister's official website hosts a section dedicated to promoting pet adoption, including links to humane societies across Canada and profiles of cute adoption prospects. (Prime Minister's Website)

Since 2006, the prime minister's official web site has included links and contact information that actively encouraged animal adoption as a pet cause of the Harper family.

The chinchilla, featured on the prime minister's Christmas card in 2013, started as a rescue animal in the Harpers' care.

Stephen Harper's other love, music, paid tribute to his taste in pets: his band's name, the Van Cats, was a play on the French translation of 24, the official residence's street address.

The Harper family was among more than 300 Ottawa-area volunteers who provided animal foster care, often for cats and kittens in particular.

Foster homes help when an animal is orphaned, recovering from surgery or dealing with other short-term health needs than mean final adoption must wait, such as a mother cat rescued while still nursing kittens.

The Harpers' final foster animals were returned to the Humane Society for adoption over the summer, so none were left homeless when Canadian electoral tastes shifted and the moving truck backed up to 24 Sussex earlier this week.

Bat house to stay?

As a vigourous public debate emerges over what to do with 24 Sussex itself, a small addition to the house initiated by Laureen might outlast the Harper's residency.

In late May, a bat house was installed in a sunny location on the exterior of one of the buildings on the property.

The Rideau Valley Wildlife Sanctuary worked with Laureen and the National Capital Commission, which manages the property, to construct the shelter.

A small group then joined her for the release back to the wild of some rescue bats who'd originated in the same part of Ottawa, in the hopes that they would find a happy home in her backyard.

Movers turned up at 24 Sussex Drive on Tuesday, as the Harper family prepares to move back to Calgary. (Chris Wattie/Reuters)

On Facebook, Laureen called bats "the most natural form of insect repellent," something that might be important at certain times of the year when enjoying 24 Sussex's gorgeous backyard view of the Ottawa River.

Unlike fostering cats, the bat house is low-maintenance, and might not have to come down while the rest of the property is vacant or under massive renovation.

A spokesman for the NCC said the agency had no further information to disclose on the future of the official residence, or its bat house.

Incoming prime minister Justin Trudeau's family has moved into Rideau Cottage, on the grounds of Rideau Hall, the governor general's official residence just across the street.

Liberal spokeswoman Kate Purchase told CBC News the Trudeau family currently has no pets.