ruffed lemurs
... that experiments have indicated that ruffed lemurs can understand the outcome of simple arithmetic operations?
... that experiments have indicated that <b id="mwC-4"><a href="./Ruffed_lemur" id="mwC-8" rel="mw:WikiLink" title="Ruffed lemur">ruffed lemurs</a></b> <i id="mwC_A">(pictured)</i> can understand the outcome of simple <a class="mw-redirect" href="./Arithmetic_operation" id="mwC_E" rel="mw:WikiLink" title="Arithmetic operation">arithmetic operations</a>?