I designed this after hearing about people almost dying from a wasp sting that got in their mouth when drinking from a can of soda. the solution is a lid that clicks on a soda can with a rotating top lid so you can open it when you want to drink, and close it when you are not, keeping wasps and the like out of it.
UPDATE: added serated edge for better grip when opening with index finger, and slightly thicker connector for more strength (may need to update further)
UPDATE 2: changed form of connector slightly for a better connection
UPDATE 3: I added a solid piece bottom part (with the same "gripping teeth" missing so it can be clipped on easily, as requested by justinds89 in the comments
UPDATE 4: created version 2 with a stronger connector. Printed it succesfully in PolyMax PLA fillament on my Ultimaker 3.
Printed (upside down) in Cubicon ABS, on a heated bed at 110 degrees celsius and a nozzle temperature of 240 degrees celsius.
Click the top lid on the bottom lid, and click the both of them on an open can of soda.