수영장에 알 낳은 이 벌레는 무엇인가요?

수영장에 밤에만 와서 알을 ㄴ낳고 가 버리는데 무슨 알인가요?그리고 어떻게 하면 알을 못 낳게 할수 있을가요?아침마다 물  빼고  하느라 힘들어요 <img src="https://t1.daumcdn.net/cfile/cafe/262E87335772FF2D27" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 011.jpg" style="clear:none;float:none;" id="A_262E87335772FF2D27999F"/> <img src="https://t1.daumcdn.net/cfile/cafe/21310D335772FF3027" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 012.jpg" style="clear:none;float:none;" id="A_21310D335772FF302723AB"/> <img src="https://t1.daumcdn.net/cfile/cafe/223517335772FF3326" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 013.jpg" style="clear:none;float:none;" id="A_223517335772FF3326DAB0"/> <img src="https://t1.daumcdn.net/cfile/cafe/242303335772FF362D" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 014.jpg" style="clear:none;float:none;" id="A_242303335772FF362D2B0A"/> <img src="https://t1.daumcdn.net/cfile/cafe/2526BA335772FF392B" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 015.jpg" style="clear:none;float:none;" id="A_2526BA335772FF392B5D97"/> <img src="https://t1.daumcdn.net/cfile/cafe/22232F335772FF3C2C" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 016.jpg" style="clear:none;float:none;" id="A_22232F335772FF3C2CEFEB"/> <img src="https://t1.daumcdn.net/cfile/cafe/242643335772FF3F2B" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 017.jpg" style="clear:none;float:none;" id="A_242643335772FF3F2BC8CC"/> <img src="https://t1.daumcdn.net/cfile/cafe/263B1E335772FF4224" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 018.jpg" style="clear:none;float:none;" id="A_263B1E335772FF42241F22"/> <img src="https://t1.daumcdn.net/cfile/cafe/2626C6335772FF452B" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 019.jpg" style="clear:none;float:none;" id="A_2626C6335772FF452BD91B"/> <img src="https://t1.daumcdn.net/cfile/cafe/26352B335772FF4826" class="txc-image" hspace="1" vspace="1" border="0" actualwidth="1024" width="1024" exif="{}" data-filename="수영장 알 020.jpg" style="clear:none;float:none;" id="A_26352B335772FF48261623"/>