Two things happen at once here, and both are hard.
You’re grieving. And you’re watching the others grieve, without being able to explain anything to them. Animals who lived with a companion often search the house, go off their food, become clingy or unusually quiet, or sleep somewhere different. It’s real, and it’s distressing to witness while you’re barely holding together yourself.
There’s also a version of this that people don’t say out loud: sometimes the one who died was your one. The others are lovely, and you love them, and it isn’t the same — and feeling that can seem like a betrayal.
You can say that here.
Things worth discussing: how the others reacted and what helped, whether to let them see the body, keeping routines steady, how the dynamic changed afterwards, and how to grieve properly when you still have animals depending on you at six in the morning.