The electron clouds around atoms do indeed repel each other if they come too close. This repulsion arises from the negatively charged electrons in each atom's electron cloud. According to the principles of electrostatics, like charges repel each other, while opposite charges attract.
In the case of helium, which has two electrons, each electron occupies its own region within the electron cloud around the helium nucleus. These electrons are negatively charged, and therefore they repel each other. This repulsion helps to maintain the stability of the helium atom and prevents the electron clouds from collapsing into the nucleus.
The repulsion between electron clouds plays a significant role in determining the structure and properties of molecules and solids. The arrangement of atoms in a molecule or a solid is influenced by the balance between the attractive forces within the electron clouds and the repulsive forces between them. This delicate balance determines the overall shape, stability, and chemical properties of the substance.