There will be notification that says you can start collecting items.
Vernon & Petunia Dursley
Objects to Collect:
1) Alarm clock
Click on the picture on the hall table to read about Vernon & Petunia Dursley
spiders runs around Harry’s cupboard
click on the clock near top of Harry’s cupboard and the numbers spin
light in his cupboard goes on and off
waving cursor over snake at the far end will make him move
Click on the Boa’s sign to read about him.
a lizard runs around the cage to the right and a light flickers on the cage to the back-right
Wait long enough and the boas’ glass will shimmer and disappear.