Mole and Butterfly collection rare drops

[chuckyt888]

Does anyone else have one of each of these collections that seems to have an extremely low drop rate? For me, it's the sunglasses and green butterfly. I have bunches of each of the other collection items and am always waiting on the next drop for these two in order to complete my next collection.

[Wollstonecraft]

I just completed the butterfly collection for the first time a few days ago. Took months to get a yellow butterfly! The mole seems a bit more generous and I have completed several of those collections.

[kc4388]

For me it's the purple one - I have loads of the other ones, but the purple butterfly is extremely elusive...