  The mystery behind the bird nest's construction is not well understood. Our
study focuses on the stability of a self-supporting nest-like structure.
Firstly, we derived a stable/unstable phase boundary for the structure at the
fixed coefficient of friction with varying geometrical parameters through force
analysis. Structures with a lower height and greater friction coefficient
between rods are more stable. The theoretical phase boundary matched the
experiment results well. Then we investigate the nest structure's stability
under applied weight. Static structures with lower height and more rods
(five>four>three) are more stable. Our theory also predicts a transition from
plastic phase to elastic phase. These theoretical predictions are all confirmed
by experiment. In the experiment, we also find that wet rod structures are more
stable than dry ones. The structures can support up to 100 times of it's
weight. Finally, we test the nest structure's stability under vibration. When
there are no weights applied, we are able to identify the appropriate geometric
configuration that can withstand the greatest vibration ($1g$ of vibration
acceleration and vibration energy up to $4\times10^{-4}$ times of a rod's
maximum potential energy). The critical vibration energy and acceleration
depend on the applied weights. They are increased by two and one order of
magnitude respectively under proper weight. We also make potential energy
analysis to explain the stability of the structure.
