The two unrelated southern sea otter pups were found abandoned in different spots along the coast of California, but they have become virtually inseparable in their new home at the Shedd Aquarium.

The male pups — named 870 and 872 for now — are the 12th and 13th rescued otters to come to the aquarium. The two, who are each now about 3 1⁄ 2 months old, arrived at the Shedd in early July from Monterey Bay Aquarium in California.

Both spent their Thursday afternoon lazing about in the Shedd’s otter nursery, closed off from public view and the Shedd’s other otters: Yaku, Kiana, Luna and Ellie.

It’ll “probably be in the next month or two” that 870 and 872 will be integrated with the other otters, said the Shedd’s senior otter trainer Tracey Deakins.

Since the pups don’t have mothers or surrogates, the task of the Shedd’s small yet hardy team of five otter specialists has been teaching the pups basic skills, from grooming to foraging.

But, as with many newborns, the most difficult part of the nursing process has been trying to get the pups to adhere to a regular schedule.

“We finally got them on the schedule where they’ll be asleep most of the night and be awake during the day,” Deakins said.

When the pups first arrived at the aquarium, the Shedd’s five otter trainers monitored the pups “24 hours, around-the-clock” — something no longer necessary now that they sleep on time.

It’s a “pretty lucky” coincidence that the two are “so similar in size and age,” despite the fact that they were discovered separately. One was brought into Monterey by a kayaker; the other was found hypothermic, washed up on a California shore.

“It doesn’t happen often that two young pups are put together so quickly, but because they’re close together in age and size, we were able to do that,” said Deakins.

And as the two began calling to each other in loud squeaks while sucking on frozen clams, Deakins added, “They pretty much do everything together” — even snuggling together to sleep.

Even as a duo, the two otters still have their own little quirks.

Pup 870 is the “independent and spunky” one who likes to sleep in the water — but will still “play with toys for hours,” Deakins said.

On the other hand, 872 is the “super sweet” one, says Deakins, who likes snuggles and attention: “He’ll come up in our laps if we bring towels in.”

The pups are fed six times a day — but they started squealing an hour ahead of their 2 p.m. feeding Thursday.

“It’s like they have an internal clock for feeding time,” Deakins said, laughing.

But within a short period of time, the pups stopped squealing and assumed a napping position with their faces up towards the ceiling, paws peacefully linked together across their chests.