Please answer the following question by reasoning step-by-step.
If a small flying animal picks up a string, where are they taking it?\nOptions:\n- bird's nest\n- park\n- guitar\n- kite\n- quark

bird's nest
A string can be used to make bird's nest.

A small flying animal picks up a string and takes it to the bird's nest.

.

So, the final answer is bird's nest