Stu, Chazz & Howard take the Rugrats to the zoo, where the employees wear animal costumes. After noticing this, the Rugrats learn that animals are people, too, as they see these ""animals"" do human stuff like eat ice cream, play with toys and sell souvenirs. When placed in a caged petting zoo, they think that they will turn into animals and remain there forever and ever. Later, when Tommy dropped his trusty screwdriver outside the pen, the Rugrats call on Dil and the real animals to help him out.

Stu & Grandpa prepare a surprise birthday party for Didi. They had everything prepared except for one crucial element -- the birthday cake, which they forgot to get while rushing to get the party together. They take the Rugrats to Bob's Fully Automated Bakery to get the cake. While there, Tommy's gift to Didi, a frog, got away, prompting Dil to try and find it while the Rugrats try to rescue Dil before he becomes a cake. Meanwhile, Betty takes Didi to an English tea shop, where waiters sing songs for every occasion -- to the tune of ""Hail Britannia"".