Read this Animal Crossing New Horizons Switch (ACNH) building guide on the Museum. Including museum expansion (art gallery), how to upgrade & unlock museum, Blather, & how to move!!!Check Out All Buildings List!
Museum - How to Unlock
Give 5 Creatures To Tom Nook
In order to build museum to your island, you need to first catch 5 different fish or insects and give them to Tom Nook. After completing this, Tom Nook asks you to find a place to set a tent for Blathers, the museum curator.
Wait For Blathers To Move In
Once you've given the bugs/fish to Tom Nook and set up Blathers's tent, he'll arrive the next day. Give Blathers 15 new specimen to unlock the museum building upgrade!
Get Recipes From BlathersCheck Out How To DIY Craft!
You Can Move Museum Location Later
As you progress the story, you will be able to move the location of all facilities. However it will cost you a lot. You need to upgrade the Resident Services buildign to do so.Check Out Resident Services Features!
Museum - How To Upgrade
Donate 15 Creatures / Fossils
Donate 15 different creatures or fossils to Blathers. Use your net, fishing rod, and shovels to catch 'em all.Check Out All Tools Recipe List!
Takes 2 Days To Finish Construction
After you've donated 15 items, the museum will be under construction for 2 days. Wait until it officially opens!
What You Can Do In Museum
Donate Fish, Insects, & Fossils
You can donate the creatures you've caught and fossils you've dug out to Blather. Note that the fossils need to be assessed before donation. Once you've donate them, Blather will display them nicely.
You Can Donate Sea Creatures As Well
After you've updated to version 1.3.0, you will be able to dive underwater and catch sea creatures. You can donate sea creatures in the museum just like fish and bugs.Check Out Sea Creatures List From Here
Ask Blather About Creatures & Fossils
By choosing "Tell me about this" and pick any creature or fossil you have, Blather will tell you little trivia about it.