Creatures will return to your Collection 48 hours after they’ve been placed in a Sanctuary. You must collect them in your Collection screen before you can place them in a Sanctuary again or use them on your Strike Team. To check how much time is left before your creatures are returned, you can select the creatures in "My Collection" with a Sanctuary icon in the top left and the remaining time will be displayed in their profile.

When creatures return, they come with a little DNA gift too! You collect this DNA at the same time as you collect your creatures, in the Collection screen.

Creatures can also return earlier if the Sanctuary resets. When that happens, the DNA gift they bring with them is scaled proportionally to the time they spent in the Sanctuary.