At a physiologic pH, uric acid loses a proton and becomes a urate ion, which then binds sodium, forming monosodium urate which crystallizes and ultimately forms uric acid stones.
Individuals with chronic gout are also at an increased risk for developing kidney stones made of uric acid, as well as urate nephropathy, which is when urate crystals deposit in the interstitium of the kidney.
They've adapted these very ornate structures for amplifying this behavior, for attracting females using their urates and having females feed on their urates for longer.