Arachnids belong to the class Arachnida, which is further divided into several orders, including Araneae (spiders), Scorpiones (scorpions), Opiliones (harvestmen), Acari (mites and ticks), and more. Each order contains different families, genera, and species, which make up the lower classifications of arachnids. These lower classifications help scientists and researchers to categorize and study the diverse group of arachnids more effectively. **

No, crabs do not belong to the arachnids. Arachnids are a class of joint-legged invertebrate animals that include spiders, scorpions, ticks, and mites. Crabs, on the other hand, belong to the class Malacostraca within the phylum Arthropoda, along with other crustaceans such as lobsters, shrimp, and barnacles. While both arachnids and crabs are arthropods, they belong to different classes within the phylum. **

Several arachnids can occur on indoor plants, including spider mites, aphids, and thrips. Spider mites are a common pest that can infest indoor plants, causing damage to the leaves and overall health of the plant. Aphids and thrips are also known to infest indoor plants, feeding on the plant's sap and causing damage to the foliage. It's important to regularly inspect indoor plants for signs of these arachnid pests and take appropriate measures to control their populations. **

The main difference between spiders and other arachnids is that spiders have two body segments (cephalothorax and abdomen) and eight legs, while other arachnids, such as scorpions, ticks, and mites, have a fused body with no distinct segments and may have six or more legs. Additionally, spiders have silk-producing glands and use silk to build webs for catching prey, while other arachnids do not produce silk or use it in the same way. Finally, spiders have venomous fangs for subduing their prey, while other arachnids may have different methods of capturing and immobilizing their food. **

To address a beetle and arachnid infestation in a basement apartment, it is important to first identify and eliminate the source of the problem. This may involve sealing any cracks or openings in the walls, floors, and foundation to prevent these pests from entering the apartment. Additionally, reducing moisture levels in the basement can help deter spider crickets, as they are attracted to damp environments. Using insecticides or contacting a pest control professional may also be necessary to effectively eliminate the infestation. Regular cleaning and decluttering can also help prevent these pests from finding hiding spots in the apartment. **

Self-luminous bodies are objects that emit their own light, as opposed to reflecting light from another source. Examples of self-luminous bodies include stars, the sun, and certain types of light bulbs. These objects generate their own energy through processes like nuclear fusion or electrical current, which produces light as a byproduct. **

No, the luminous clock is not radioactive. The luminescence in the clock is typically achieved using a phosphorescent material that absorbs light and then slowly releases it over time. This process does not involve any radioactive materials. The glow from the clock is simply a result of this light-absorption and emission process. **

A luminous point is a theoretical concept used in physics and optics to represent a source of light that emits light in all directions. It is often used as a simplification in the study of light and its behavior, allowing for easier calculations and analysis. In reality, a luminous point does not exist as a physical object, but it is a useful tool for understanding the behavior of light in various systems. **