CREATE TABLE table_25687 ("Episode Number" TEXT, "Title" TEXT, "Villains" TEXT, "Director" TEXT, "Writer" TEXT, "Original airdate" TEXT)

Who were the directors of the episode 'nano nits' written by nathan cockerill?
SELECT "Director" FROM table_25687 WHERE "Writer" = 'Nathan Cockerill' AND "Title" = 'Nano Nits'
SELECT "Director" FROM "table_25687" WHERE "Title" = 'Nano Nits' AND "Writer" = 'Nathan Cockerill'