Thelytoky is when certain insects and animals, like bees and wasps, can make babies without a dad. This is because the babies are made using only the mom's genes.
Usually, when babies are made, they have genes from both a mom and a dad. But with thelytoky, the babies only have genes from the mom. This can happen because the mom has special cells called "parthenogenetic cells" that can make baby bugs without a dad's help.
Thelytoky is really cool because it means that these bugs can make lots and lots of babies without needing a male partner. However, it also means that the babies will all have the exact same genes as the mom, which can be good or bad depending on the situation.